Check your OIL PUMP NUT!

[slcook54]

Note: I already posted this in the stickied thread at the top of this forum, but I thought I would share my experience for those who haven't encountered this problem. For more information, check the thread stickied at the top of the forum including full DIY write-up.

WTF!? Okay guys, get this. My buddy and I have been planning to do the oil pump nut for 2 months now, and we finally got around to it yesterday. We decided to sacrifice my car as the guinea pig since he is still having a full cage built. Anyways, his cage builder offered us accessibility to his lift, which we were very thankful for.

For some reason we both forgot about the engine hoist, so Alex's (aweather)'s cage builder fabricated an engine hoist for us in about an hour. It was amazing, it followed the same design as all the other ones we have seen, so we deemed it to be structurally sound. Well, after lunch we start on the oil pump nut, we wanted to print the directions provided by Chad, but Alex's printer wasn't working so we summarized the steps and wrote them down. We figured that and the Bentley would suffice.

Everything was very simple, removing underpanel, swaybar, x-brace, dipstick, power steering, etc. Then we got to the oil pan and for some reason didn't unscrew the control arms from the body which you should DEFINITELY do to save time, we were able to squeeze the oil pan out nonetheless, but on the re-installation we took them off which made life much easier.

So the moment we were all waiting for, we pull off the oil pan and THE NUT WASN'T EVEN ON! We searched the entire oil pan and it wasn't to be found, but we did find one of the four screws used to hold the sproket in place. The arrow is pointing to the screw that had backed itself off, not including the oil pump nut. (This is not my OIL pump, just a picture from another thread)
http://img.photobucket.com/albums/v133/slcook54/backedoutnut.jpg
Steve, Alex's fabricator suggested the oil pick up might have sucked it up, sure enough there was the nut, in the oil pickup. Another trip and I could have lost my engine, what a relief. We tack welded the nut in two spots, changed the motor mounts, refilled the oil and power steering fluid and called it a day.

What a relief. CHECK YOUR NUT!!!!
PS. My car is a 95 M3 with 74000 miles and URI crank pulley, to date, I have spun out twice, only once did I not get he clutch in.

[Chongus]

You are making me paranoid. I have neither the resources nor time to do this. :(

[slcook54]

The lift really did make life easy, but without one, you could easily do it in 6-8 hours.

[JClark]

Holy crap. I bet you had a little freak out eh? Makes me wonder how mine is doing in there. I dont have the access to a lift until the spring so I'm trying to wait.

[slcook54]

Yeah, I was freaked, but more relieved, one more week and I would have been toast. Funny thing was I was contemplating doing the auto-x or the oil pump nut, looks like I made the right decision.

[Speedlimits?]

does this affect all years all engines?

[DocWyte]

Hmmm. I have 108k miles on the motor already. Figure I'll just wait for it to cook itself. If the nut was off, the motor would've lunched itself long ago.

How many miles are on your car?

[EThirD]

Does the oil pump issue also affect the M50B25? Just curious, nice to have my little tank of an M20 :)

[slcook54]

does this affect all years all engines?
Yes.


Hmmm. I have 108k miles on the motor already. Figure I'll just wait for it to cook itself. If the nut was off, the motor would've lunched itself long ago.

How many miles are on your car?
74K miles and change. There is no guarantee you will avoid damage when it does pop off, even if you turn the car off immediately.


Does the oil pump issue also affect the M50B25? Just curious, nice to have my little tank of an M20 :)
Not sure about M20 motors.

[BSH]

does this affect all years all engines?Yes. Even the euro motors. They all have a similar oil pump setup. Check yours now!!

[jonnyg]

You are making me paranoid. I have neither the resources nor time to do this. :(


Seriously, me too.

[Ali]

hmm, i wonder if the crank pulley has anything to do with this...

[M3corey]

doubt it

[slcook54]

Some said it does, no direct evidence, but just thought I would list that anyways.

[Balthazarr]

Hard for me to fathom how a left handed threaded nut can back off with a clockwise rotation.
So when spinning the car, there is a counter torque when the engine shuts down?

[AntiHero]

I hate reading these threads :(. I dont have a hoist and im really lazy. Well I guess when I have the broken car i'll wish i did it

[JClark]

Anti-hero: we need to organize a northeast oil pump nut day. Thats the only thing that will get me to do it.

[Estoril4dr]

This happened to my friends car this month with a 97 m3. He was driving on the freeway when his oil light came on. Within 10 seconds, his engine shut down and would not start. He is now without a car.

[slcook54]

Anti-hero: we need to organize a northeast oil pump nut day. Thats the only thing that will get me to do it. Jesse, on the first time, without a lift, you'll probably need a full day for one car, about 8 hours give or take on your work methods. Second time around though, everything will go much faster, I'm sure.

[Hammdy]

When you welded the nut on did you clean off the oil first? Once when I did it I cleaned it up nicely (with brake/parts cleaner) to prepare for the weld then welded it and there was a nice flash fire. I've been thinking what else could be done besides cleaning off the oil with flammable fluids.

[///AlpinePower]

Hard for me to fathom how a left handed threaded nut can back off with a clockwise rotation.
So when spinning the car, there is a counter torque when the engine shuts down?

yeah, the road

[Gene V]

Mine is locktited and the threads centerpunched...knowing that it's secure is a great relief...

[slcook54]

When you welded the nut on did you clean off the oil first? Once when I did it I cleaned it up nicely (with brake/parts cleaner) to prepare for the weld then welded it and there was a nice flash fire. I've been thinking what else could be done besides cleaning off the oil with flammable fluids.
Yeah, we cleaned it up nice however the whatever it is coated with, zinc, I'm assuming didn't make for the cleanest welds, however, still much cleaner than the picture above.

[POPS M3]

I know what the next project for my car is.

Thanks for the post

Ken

[Luftwaffe1O1]

i cant beleive this was never recalled :(

[Balthazarr]

i cant beleive this was never recalled :(

I can...too expensive for BMW to fix in their estimation. So the onus is on the car owner.

[Balthazarr]

yeah, the road

Got it...both feet in.

[Luftwaffe1O1]

Well whats the ratio of people who have had this happen on a stock car vs someone with URI crank pulley?

[Balthazarr]

Maybe start a thread for people who have lost their nut :) or found it loose like what Clumpy did with the MS thread.
Calculating the ratio should be easy enough from that with enough respondents.

URI is probably the most popular cp, but anybody with a cp would be valuable info.

[slcook54]

Well I spun at the Auto-X and didn't get the clutch in quick enough, it is much more likely this contributed to the backing off of the nut than the pulley.

[BJO]

I can...too expensive for BMW to fix in their estimation. So the onus is on the car owner.

Not as expensive as the new e46 m3 connecting rod bearing replacements.

I had my shop do the oil pump nut last month. They found it was tight, but he loctited anyway. My motor mounts were in bad shape and I did those as well. I have 128k and auto-x at least 15-20 times a year.

[Gene V]

i cant beleive this was never recalled :(

Why do a recall, it happens to cars that are out of warranty coverage...

[Black95///M3]

I am about to change my oil pump nut but I don't have a torque wrench. Can I just crank it on there real tight?

[slcook54]

Buy a torque wrench, what were you planning to do when you had to put the oil pan back on to seal the gasket correctly and evenly?

[Balthazarr]

I am about to change my oil pump nut but I don't have a torque wrench. Can I just crank it on there real tight?

Just fasten it down? It should be welded or safety wired and maybe loctited as well.

[JClark]

Jesse, on the first time, without a lift, you'll probably need a full day for one car, about 8 hours give or take on your work methods. Second time around though, everything will go much faster, I'm sure.

Slcook- Thanks. I'm hoping I can get a buddy and do our cars one right after the other one weekend.

[JClark]

Can someone go into more detail on the spinning and countertorque on the nut?

How does clutch in/clutch out make a difference? What's better?

[Balthazarr]

Can someone go into more detail on the spinning and countertorque on the nut?

How does clutch in/clutch out make a difference? What's better?

OK, from the previous response "the road" I figure that when the clutch is locked and the rear wheels catch the surface of the road it forces the drive train in the opposite direction.
hence the left handed thread would loosen. That's my take.

[Balthazarr]

I used to think there was a more elegant explanation ie gyroscoping motion...two planes of rotation.
The above is much less complex.

[JClark]

Thats the understanding I got too but I just wanted to see if anyone had a prettier explanation (like you said, involving physics etc).

[95MMM]

i think this was covered in the stickied thread, but anyone know how much a typical shop would charge to check and tighten the nut?

[BJO]

my shop charged 4.5hrs labor. $390 after tax and CCA discount.

[slcook54]

It should definitely not take more than 5 hours for a shop to do it, we did it our first time in 5 hours, not including cleaning up, lunch, dinner, etc.

[EstorilBlauM3]

Just wondering about something... Many people have claimed this so called oil pump nut failure to be a very big problem. If the oil pump nut has been off for sometime on people's cars, and people don't know about it until they actually take apart the whole oil pan, etc. How can one conclude that loose nut was the cause of engine failure, and or other problems? Thinking about it logically, it just doesn't seem to make any sense. I'm curious to find out how many people actually took the time to take apart eveything and examine this nut and see if it was really loose or not. We already have one person who had the oil pan taken off and the nut was still tight. I just hate to see paranoia spread about this nut from a few incidents...

[Balthazarr]

Just wondering about something... Many people have claimed this so called oil pump nut failure to be a very big problem. If the oil pump nut has been off for sometime on people's cars, and people don't know about it until they actually take apart the whole oil pan, etc. How can one conclude that loose nut was the cause of engine failure, and or other problems? Thinking about it logically, it just doesn't seem to make any sense. ..

Not sure I understand the question.
If the nut was loose or had fallen off, eventually there would be a problem.
Some people caught it in time, others didn't and had damage.
You lose oil pressure and drop the pan to find the nut was off allowing the sprocket to fall off, conclusion is loose nut was the cause.

[///MacDaddy]

Besides a new oilpan gasket any other parts needed for this job?

[JClark]

...I just hate to see paranoia spread about this nut from a few incidents...

O trust me, it's already spreading fast.

[vjlax18]

One thing with welding the nut back on... it throws off the balance of everything. Loctite and punched threads work the best in the long run. And replacing the oil pump while you are in there is also a good idea.

[ChadsM3]

Just wondering about something... Many people have claimed this so called oil pump nut failure to be a very big problem. If the oil pump nut has been off for sometime on people's cars, and people don't know about it until they actually take apart the whole oil pan, etc. How can one conclude that loose nut was the cause of engine failure, and or other problems? Thinking about it logically, it just doesn't seem to make any sense. I'm curious to find out how many people actually took the time to take apart eveything and examine this nut and see if it was really loose or not. We already have one person who had the oil pan taken off and the nut was still tight. I just hate to see paranoia spread about this nut from a few incidents...

1. The nut holds on the chain-driven sprocket to the oil pump shaft.
2. That nut, if loosened can fall off.
3. If that nut falls off, and the sprocket releases from the shaft, you will have no more oil to the engine. Simple as that.

Paranoia? Maybe some. Good reason? Yes.

Folks...here's some info I recently found. After speaking to a BMW Factory Tech on this issue, it is widely known that this is an issue for cars with this type of oil system. Secondly stock motors can have this problem arise if the motors are bounced off the rev limiter many times. Moreover, mods, such as crank pulleys and LTW flywheels tend to lend themselves for a quicker reduction in engine spooling speeds. So in combination with the possible track spinning (and reverse the drivetrain) as well as the above mentioned, the nut can work its way off. Not good. And confirmed...this is a problem, and BMW DOES know about it. If you daily drive your car and don't do anything crazy with it, you are probably ok. But, if you track you car, autoX your car, do burnouts, etc...Go get it checked or fix it yourself. Just open the thread that I wrote for fixing this issue. It may help.

-Chad

[ChadsM3]

Guys - go buy a Repair manual and READ THE PREVIOUS O.P.N. THREAD. sheesh...

http://forums.bimmerforums.com/forum/showthread.php?t=228123

[Bassmaster]

One thing with welding the nut back on... it throws off the balance of everything. Loctite and punched threads work the best in the long run. And replacing the oil pump while you are in there is also a good idea.

How is a sm spot weld on a nut going to throw off the balance of anything? Thats rediculous.

[///MacDaddy]

How is a sm spot weld on a nut going to throw off the balance of anything? Thats rediculous.


I don't know about rediculous, but when I do mine soon, I'm going with locktite and punching the threads route. That is more than enough IMO. Locktite alone would probably be enough but punching the threads is just for extra insurance and piece of mind. Maybe if I had a welder I would throw 2 spots on opposite sides of the nut, but I don't think it's necessary.

[vjlax18]

How is a sm spot weld on a nut going to throw off the balance of anything? Thats rediculous.

Have you looked at the nut? How small it is? Do what you want, but "rediculous" is not a term used well here.

[adsingl]

Another description that might help - let's make the physics very practical/easy to see here. If you already understand why we have this situation, don't bore yourself w/this post!
The threads are left-handed, so normal engine rotation "turns into" the nut or would tend to keep it tight. But, even though the engine doesn't change rotation direction, upon deceleration the torque forces do. Try to visualize this, look at pics in previous posts. The sprocket is on a splined shaft, but there is *some* play between the splines on the shaft and those on sprocket. My parts, under magnifying glass, showed no real wear (45k miles)on the splines (I could see the tooling marks from where the spline was produced, either punched or drawn thru tooling). Point is, little to no wear or these marks would have been gone. So there is some tolerance, play, if you will, between these splines, say less than 1 degree of rotation, but it doesn't matter how much, fact is there is some, before tightening the nut; one can rotate the sprocket on the shaft just a bit, as one would expect with anything less than a press-fit.

So, any time one downshifts to use engine "braking", or has a spin that does the same thing, OR has a "mechanical overrev" from mis-shift or wrong gear, you're suddenly changing the direction of torque of every shaft in the drivetrain, from wheels, axles. driveshaft, tranny, crank (getting closer, eh!?) the sprockets on the crank, to the chains on the end of the crank, then finally to the sprocket on the oil pump (and the cams, but different attachment/no worry here). In these cases, instead of the engine accelerating the wheels, the wheels are trying to (and do) accelerate the engine RPM's. Since there IS some play in the fit between the sprocket and oil pump shaft, this "reverse acceleration" torque that we've traced to the sprocket, is now on our little $.30 nut. Some hold, some don't.

I saw no evidence of loctite being used originally, so we cleaned the sprocket and shaft splines with acetone, loctited, and overtorqued the nut some (forget values, but not too much, it is avery thin nut). I chose not to weld.

As I think about this, two very thin teflon washers with an outer diameter equal the to outer dimension of the nut, between the nut and sprocket, would've been a different approach or solution to this. That is, let the spocket move, just don't let it affect the nut - but this is an untested idea, not suggesting anyone go this way.

For the "doesn't a weld throw balance off crowd/debate". Well of course it does, unless you're perfect in volume displacement and offsetting positions, *BUT* this close to the center, I doubt very seriously it could have an effect. I've seen one picture of welds that - well, let's say appear to be of the "more is better" approach, but my gut tells me hthere is no problem here at all. And guess what, I don't see any evidence of balancing on the spocket (because it's mass and diameter make it unnecessary); again leads us to believe the welds are negligible.
ADS

[EstorilBlauM3]

1. The nut holds on the chain-driven sprocket to the oil pump shaft.
2. That nut, if loosened can fall off.
3. If that nut falls off, and the sprocket releases from the shaft, you will have no more oil to the engine. Simple as that.

Paranoia? Maybe some. Good reason? Yes.

Folks...here's some info I recently found. After speaking to a BMW Factory Tech on this issue, it is widely known that this is an issue for cars with this type of oil system. Secondly stock motors can have this problem arise if the motors are bounced off the rev limiter many times. Moreover, mods, such as crank pulleys and LTW flywheels tend to lend themselves for a quicker reduction in engine spooling speeds. So in combination with the possible track spinning (and reverse the drivetrain) as well as the above mentioned, the nut can work its way off. Not good. And confirmed...this is a problem, and BMW DOES know about it. If you daily drive your car and don't do anything crazy with it, you are probably ok. But, if you track you car, autoX your car, do burnouts, etc...Go get it checked or fix it yourself. Just open the thread that I wrote for fixing this issue. It may help.

-Chad


Guess I'll be okay since I don't track or autoX my car. I also dont have a crank pulley or LTW flywheel.

[slcook54]

Guess I'll be okay since I don't track or autoX my car. I also dont have a crank pulley or LTW flywheel.
Robert, you might be safe, but you aren't guaranteed anything.


Besides a new oilpan gasket any other parts needed for this job?
Not neccessary, but I went ahead and changed the motor mounts, you will also need power steering fluid, motor oil obviously, I also used a new nut and finally the gasket like you said. Few other random things to have, gasket sealer, brakleen, locktite. I also went ahead and changed the power steering hose clamps as they were leaking, and I don't know the name of that style clamp, but I switched to the type where it requires a screw to tighten it.


Have you looked at the nut? How small it is? Do what you want, but "rediculous" is not a term used well here.
John, I still think your comment about "throwing everything off" is a little too exaggerated. I did two tiny welds, equal size, opposite of each other and they are so close to the rotational center that I doubt it will have any negative long term effects.

[EstorilBlauM3]

I'll take my chances...

To be honest with you guys, I've gotten paranoid for really no reason about a lot of things from reading this forum on so called "common e36 M3 problems that REALLY need to be taken care of or your car is @$#" that I'm really done dumping money, time, and effort until something really breaks and I know it for sure. My list of unecessary things that have been replaced on my car is pretty damn long, and a lot of hard earned money has been spent for no reason... That is why I'm really skeptic about this problem. The physics and descriptions of the actual problem are all sound and all, but I'm not in any way paranoid about it.

[m3fuz]

You are making me paranoid. I have neither the resources nor time to do this. :(

Same here...too busy, but thanks for the head's up slcook. I'm sure I'll be posting about how the oil pump nut went bad in a few months and that I'm stuck.

[eightballrj]

adsingl,
Good call. But, if it did have play in the splining then its should have shown some pressure wear from the play. But, you never know?? I was really just showing that one spin or so with reverse rotation of the motor to cause the nut to become loose. But, I guess if it was on its way to being loose then that could have been the straw that broke the camel's back. Haha, who knows. I guess I will check mine too when I do my waterpump.

Richard

[BJO]

FYI, there is a bmwcca clubracing bulletin out on the oil pump nut issue. you all should be fine if you do not auto-x or track, but since these cars are getting up there in miles and years, it makes sense if you want to keep your car longer. i did it just cause I auto-x twice a month. I can't convince the wife I need an new motor, but the $400 for the oil pump nut was doable.

[Balthazarr]

So, any time one downshifts to use engine "braking", or has a spin that does the same thing, OR has a "mechanical overrev" from mis-shift or wrong gear, you're suddenly changing the direction of torque of every shaft in the drivetrain, from wheels, axles. driveshaft, tranny, crank (getting closer, eh!?) the sprockets on the crank, to the chains on the end of the crank, then finally to the sprocket on the oil pump (and the cams, but different attachment/no worry here). In these cases, instead of the engine accelerating the wheels, the wheels are trying to (and do) accelerate the engine RPM's.

You're saying the deceleration will create a counter torque which the oil sprocket will experience with the clearance you described even when the drivetrain is rotating in the proper direction?
So no-one should ever engine brake?

I suppose intuitively it makes sense
Do you have a particular rpm range in mind where this is critical?
Please clarify.

[Bassmaster]

Have you looked at the nut? How small it is? Do what you want, but "rediculous" is not a term used well here.

Have you looked at the nut?Asking how sm it is make me think you have not?....yes I have and spot welded it...thats the reason I know saying a spot weld on on the center of the sprocket is not going to unbalance anything. I think I know my motor inside and outside very well.

*I fixed my nut while in the process of a rebuild for forced induction....which was on very tight @ 80k miles on my 95.

[rommelrules]

You're saying the deceleration will create a counter torque which the oil sprocket will experience with the clearance you described even when the drivetrain is rotating in the proper direction?
So no-one should ever engine brake?

I've been engine braking for well over 180K and my nut is fine.
Err... let's keep a cool head here. Come on, guys. This is almost getting ridiculous.
People talking about class action law suits, recalls, catastrophic failures left and right... :rolleyes
On top of that, everybody seems to be randomly throwing all sorts of theories
as to why this happens and there's just too many variables.

I don't know, before everybody goes into hysterics (or convulsions)
maybe you should read EstorilBlauM3's post-- He seems to be the only one making sense.
I don't have time to type my version.
Or, read Mr. Turner's letter about this same problem on Roundel.
He may know a thing or two more than you.

DO NOT PANIC. The world is not coming to an end.
Your nuts are probably fine unless you're a track/autocross junkie.
The odds of you crashing your car are far, far greater than
your much feared nut failure. Jeez...
I swear, these threads on the nut failure are a very
interesting sociological study...

Now relax and go have a beer.
Or a gin and tonic.

[slcook54]

DO NOT PANIC. The world is not coming to an end.
Your nuts are probably fine unless you're a track/autocross junkie.

? I have been to one auto-x to date where I spun (bald tires) and didn't get the clutch in fast enough, this occured over 10K miles ago. Other than that, there is no reason my nut should be off unless there is added stress with my crank pulley. This is a very real problem, my experience alone is evidence to that. If I had approached this with Robert's or your mentality, I would probably be looking at quotes to have my engine rebuilt right now. I didn't mean for this thread to go in the direction it has been, I was merely sharing my experience with others. However, to deny that this is a problem on E36's is somewhat naive IMO. Obviously not everyone will have the problem, but, that is not to say that everyone will be problem free either. I see it as being one step ahead of the game. I don't have to ever worry about it again, something 5-6 hours of my own labor was definitely worth, whether it is worth it to you is completely your decision.

[Balthazarr]

Which issue of Roundel would that be?

I read EstorilBlau's post and I answered it, but I thought there was some ambiguity with the way he worded it.

WRT the engine braking, I don't think that happens either bc the pump sprocket has positive rotation even if there is some play on the splines.

I just wanted adsingl to give some feedback.

[rommelrules]

Which issue of Roundel would that be?

December 2003. Tech section.
Can someone scan this and post it (if it's not a repost) for everyone's edification, perhaps?

[Balthazarr]

I have that...somewhere. :laugh

[Balthazarr]

Just read it...he doesn't say much at all.
Most failures he ASSUMES were on cars that were tracked sometime in their life.

[Balthazarr]

I'm going to ck mine and secure it anyway...hopefully very soon.

[EstorilBlauM3]

Which issue of Roundel would that be?

I read EstorilBlau's post and I answered it, but I thought there was some ambiguity with the way he worded it.

Sorry about my first post. It was a little ambiguous. I guess my point from my other posts that I wrote is if this is really that big of a deal/problem. I'm in no way saying that this is not a problem. The explanations from the other members seem to be sound and there are cases of this nut backing out and falling off. However, there seems to be a lot of paranoia surrounding this whole oil pump nut failure and other common e36 items that need to be replaced ASAP or one's car is screwed. It seems to be bordering on OCD for this whole oil pump nut thing. I just don't want the members here to waste his/her time or money on unecessary work until it really needs to be done. There just seem to only be a handful of incidents where the nut was loose or not even there. Other people who have taken the time to examine their nut have said that it was tight. Both groups have had track time and autoX.

Again, as I've said before, I've been severely paranoid in the past about common e36 problems that "needed to be rectified or else"... All of this paranoia was for NO reason after I do all the work and examine the parts that have been replaced. Believe me, the list is quite long about things that were replaced that didn't have to be. Really, why spend the time and money when one doesn't have to? I love my M3 and all, but it just seems that a line has to be drawn somewhere between "standard preventative maintenance" and "e36 preventative maintenance OCD"

Let's just keep it real guys. The e36 has been out since 1992. If this is such a common problem on the e36 platform and other cars with this type of oil pickup system, where is all the evidence besides the few cases floating around the forums? There are many of these cars in the world.

As I said before, I'm not worried about this nut problem. If my idot light for oil comes on while I'm driving my car, I'll do the logical thing and stop immediately and get the car towed. I'lll then deal with the problem, if it ever happens that is... And if the worse case scenario comes up where a new motor is needed from the nut failure, I'll probably choose not to repair the car. I'll just sell off the parts and add that to the money that has been saved by not performing uncessary work on my e36 and buy a new car.

[Balthazarr]

That's fine Robert, I fully understand where you stand on this.
For me though, I figure a few hours grunt work and some slime would be well worth the peace-o'mind.
Just pisses me off that with all the other work I WANT to do, this I have to do.
Plenty of other maintenance work without this.

[95cosmom3]

does this affect auto cars?

[vjlax18]

Have you looked at the nut?Asking how sm it is make me think you have not?....yes I have and spot welded it...thats the reason I know saying a spot weld on on the center of the sprocket is not going to unbalance anything. I think I know my motor inside and outside very well.

*I fixed my nut while in the process of a rebuild for forced induction....which was on very tight @ 80k miles on my 95.

Yes, I dropped the nut a month ago. I also blew a head gasket 2 weeks ago and I will be pulling the entire motor and tranny out within the next few weeks. That's great that you know your motor... I know mine too. ;)

[adsingl]

I believe a calm head is best here too. I guess I'd read about this right after buying my M3 July 2003 and honestly completely forgot about it, so a part of me would say I'm not sure I'd do this preventatively if it hadn't have come off, then my memory kicks in and I obviously forgot about it did nothing until it came off!
As long as you shut your engine off as soon as it is safe you should have no damage. I hope this doesn't start some arguement-there's always an exception. But I ran for 2 miles after light went on *DON'T DO THIS* - I got REALLY lucky, had no damage from pressure loss. I know, I inspected bearings (had a friend who builds several types of race engines look at it), and did two oil analyses, one as I took the pan off and another after restoring pressure, to ensure no bearing metal in the oil. Now I did continuously reduce rpm's until I got off the x-way (almost no load), my oil had about 4500 miles on it (filter change at about 3k). And the oil DID smell burned at the rod bearings, so damage was imminent. But I think you have time to get to a shoulder - say 30 seconds/no upward revs. Then - other than a tow job, the repair is no different than if you did it preventatively.

I'd say if your oil pressure sensor is known to be malfunctioning, I'd fix that!
Along the lines of Mr Blau, I don't think many of the things folks say to do are needed before failure if you don't drive long sections of remote hiway. Old water plastic impeller pumps maybe, but most pumps leak, make noise, or temp guage will start to rise over time before failure, plastic therm housing will virtually NEVER fail until you do new thermostat, so get one when you want/need to do thermostat, combine that with coolant flush, etc.
ADS

[GGray]

I put a 48k 3.2 motor in my car the nut was barely tight. I locktighted mine and added a few more inches of torque, and punched the threads. I think the main culprit is the factory uses low torque value on the nut from the factory. The torque number is a less on the S50/S52us motor than on my old M20/S14 motors I have built.

GGray
95 3.2 M3 with toys

[Bassmaster]

Yes, I dropped the nut a month ago. I also blew a head gasket 2 weeks ago and I will be pulling the entire motor and tranny out within the next few weeks. That's great that you know your motor... I know mine too. ;)

Off topic:
The www.vacmotorsports MLS head gasket in .070(stock) will cure your HG problems. Use a set of ARP head studs. machine the head to a high polish, then coat the HG with permatex copper seal. Sorry for the neg tones
:) I've done the HG thing 3 times too many.

[vjlax18]

Nah, ran without oil pressure while autoxing 2x in a month. I'm not taking any chances on fixing it, then having it happen again. My new BMW crate motor will be ordered soon. :)

[adsingl]

You're saying the deceleration will create a counter torque which the oil sprocket will experience with the clearance you described even when the drivetrain is rotating in the proper direction?
So no-one should ever engine brake?

I suppose intuitively it makes sense
Do you have a particular rpm range in mind where this is critical?
Please clarify.
---------------------------------------------
Yes, I believe deceleration imparts untightening force against the nut. That does NOT mean it loosens it in all cases. In my case, bought the car w/33k miles, no mods, no track. At 45k miles, I money-shifted. 20 seconds later, oil light came on. So my supposition is this would have eventually happened at some point, the money shift caused it to happen sooner versus later.

No, I'm NOT suggesting no-one should engine brake. My car is back together, I'm already downshifting; with some loctite and extra torque on the nut, I'm not even worried. If it does happen again, I may tack weld but it won't take me half the time now that I'm experienced! If I can't drive it how I like, may as well not own it far as I'm concerned.

So yeah, I think a spin that actually reverses engine direction puts even more force against the nut, no question. But a (probably weak but gets the idea of forces across) comparison may be river against limestone. A flood/rushing water will wear away the rock (high force/track spin) quickly and more dramatically than slower but continuing flow of the stream (lower yet still there/downshift), but it is also a force that will wear the rock down.
But hey, maybe the original owner lied and spun it 6 times... Seems unlikely based on how he cared for the car, his house, etc. Ultimately, again, it is not a press fit; I don't think mine was unique in having a minute bit of angular rotation with the splines mated.
ADS

[nightkrawler]

for all the guys that replied, this is making me nervous, ditto! i agree, and i dont have the time or equipment to do this job either. nor do i feel like i should have to pay a mechanic a considerable amount of money to do it for me. if this is happening so frequently to people. cant we get a petition going to bmw to try and get a recall on this? or is it mostly cars that are tracked where this is happening. obviously if it's track cars mostly, bmw is not going to do anything about it. but i think it's worth a shot. and if not this issue, then definately the money shift problem. there should definately be something done about that imo. as i said, it's worth a shot. and im sure we could get 1000's of people to get in on a petition or email. hell, i'd even take the time to set up a website where people could go to register their complaint and we could all send the link to bmw everyday. i dont know if it's a stupid idea or if anything will ever be done. but i think this situation really sucks and something has to be done imo.

[DocWyte]

Considering the newest e36 M3 is 6 years old now, and most on the site are older than that, trying to get BMW to cover this is pure folly.

For every person who's had an oil pump nut come off, there are probably 100 or more who haven't.

If you're not willing to do the job yourself, why do you feel you should have to pay a mechanic to do it? Esp considering that it's probably not an issue...

[nightkrawler]

well it seems to be a big issue on this board, the thread is even pinned. just makes me nervous when i keep hearing about this happening. i dont track/race my car, so i hope i have less to worry about. and as to the money shifting, i have heard of this happening to people and bmw covered the repair. they know this is a know issue.

[DocWyte]

Money shifting is entirely driver error. Maybe BMW covered it for a few people who were still under warranty, but I can guarantee you they won't if your car is 10 years old like ours is.

Like most things on the board, I think the oil pump nut issue is completely blown out of proportion, just like the rtab's, and radiator failing every 20k miles or something.

[rommelrules]

well it seems to be a big issue on this board, the thread is even pinned. bmw covered the repair. they know this is a know issue.

Maybe you should look at the number of people on this board
and the number of M3's still running and without nut problems
before assuming it's an issue that warrants a recall...

For every M3 poster with a nut failure on this board,
there's hundreds of M3's out there.

There are actually M3 owners who don't do the whole forum thing.

[rommelrules]

Like the rtab's, and radiator failing every 20k miles or something.

Yeah, that's actually my favourite one.
RTAB's failing every 20K miles... :rolleyes

[slcook54]

Not once have a read anything about a radiator failing in 20K, no need to exaggerate. If you don't think it is a problem then more power to you. You can be naive regarding the possibility that the nut will back off, I chose not to and it saved my engine. I didn't post this thread to prove anything merely to inform fellow enthusiasts of my experience. I'm not looking for BMW to issue a recall, I enjoy working on my car, if others don't, well that is not my problem. The reason this thread is relavent is because enthusiasts tend to drive their cars more spiritedly than the average M3 owner. Mostly everyone on this board has mods or is planning on some, and since some speculate that certain mods affect the nut, I think the issue is very important for modded M3s.

[DocWyte]

Man, everyone here lately just has a huge stick up their a$$! Yes, of course I was exagerrating! I was making a point, which is things here get completely over blown.

Does the oil pump nut come off sometimes? Yes! As proven by slcook54 and others. Is it an all encompassing problem? No, I really don't think so, esp not enough to force bmw to do some sort of recall on it. I've got 108k hard miles on the car and it's running strong. I'm more than willing to roll the dice and continue driving, but that's just me. If you want to be cautious, then by all means do so, but don't expect bmw to cover the costs involved.

[slcook54]

I never once suggested that people should issue a recall or contact BMW. Is it a sure thing the waterpump fails at about 60K, no, but does it occur frequently, yes. I decided to change my waterpump instead of waiting for it to fail leaving me stranded on the side of the road. I could really care less what you think of things getting overblown, I don't see how this thread has overblown the issue of this problem. How many people have you seen in the E36 M3 forum recently post about failed waterpumps, generally, not many, because the majority of enthusiasts know this is an issue and address it beforehand, just like radiator neck hoses failing at 100K. Take your chances if you want, I could really care less, but I still think people ought to be informed.

[EstorilBlauM3]

nighkrawler,

If I was you, I wouldn't worry about this issue. Don't lose any sleep over this. If your car wants to tell you something, it will do so by making noises or showing the proper indicators on the cluster. Never assume that your car is trying to tell you something when it really isn't.

I have used this method of communication with all of my cars and they are all healthy and strong to this day.

[EstorilBlauM3]

Yeah, that's actually my favourite one.
RTAB's failing every 20K miles... :rolleyes

The "change the RTABs because if you don't, the sheet metal on your subframe will be torn, and then you are @#$" is one of my favorites too... I'm glad that when I took mine off at 99,102 miles, they were both still fine and so was the sheet metal... I'm glad I wasted time and money for that unecessary preventative maintenance.

Another one of my favorites is the "poorly designed underpanel that falls of right when you drive the car off the lot"... It is interesting that mine lasted 8 years and about 108,000 miles before it failed. I have friends that had their underpanels last just as long too...

[EstorilBlauM3]

I never once suggested that people should issue a recall or contact BMW. Is it a sure thing the waterpump fails at about 60K, no, but does it occur frequently, yes. I decided to change my waterpump instead of waiting for it to fail leaving me stranded on the side of the road. I could really care less what you think of things getting overblown, I don't see how this thread has overblown the issue of this problem. How many people have you seen in the E36 M3 forum recently post about failed waterpumps, generally, not many, because the majority of enthusiasts know this is an issue and address it beforehand, just like radiator neck hoses failing at 100K. Take your chances if you want, I could really care less, but I still think people ought to be informed.

Steve, I think some of the members feel that this issue is overblown because of how the posts have been worded. From reading the many posts about the nut, the people who have suffered from this problem portrayed a situation that all e36s WILL have this problem and that people better CHECK THE NUT ASAP OR ELSE. That kind of definitive and conclusive attitude/communication brings about exageration and paranoia. I'm in no way questioning your ability and knowledge on the e36 platform because I know from personally talking to you that you know your stuff. I'm just concerned on the way things are brought about here on the board. I guess in the end, it is just differences in thinking, methods, etc.

[Balthazarr]

The title of this thread sounds like an alarm and regardless of recall, which is a preposterous notion at this point, I think it's prudent to take the precaution of checking.
As has been said numerous times here folks, do whatever you want.

[vjlax18]

People get excited when they think about having to pay $6-7k for a new motor because a simple (TINY) nut backs itself off. That's why these threads sound the way they do sometimes.

[adsingl]

well it seems to be a big issue on this board, the thread is even pinned. just makes me nervous when i keep hearing about this happening. i dont track/race my car, so i hope i have less to worry about. and as to the money shifting, i have heard of this happening to people and bmw covered the repair. they know this is a know issue.
---------------
Re: Money-shifting, I put this in my append only as it was a related event whose forces involved may have/probably hastened the nut coming off, but as DocWyte offers, a money-shift is driver error in almost all cases, certainly mine was. Also as stated, but I'll re-phrase, you don't exactly have a good sample of the whole e36 population on this board; way more folks don't have this occur than do.
And one last time (from me at least) - TURN YOUR ENGINE OFF IF IT HAPPENS and it is extremely likely the only added cost to a preventative fix is a tow job.

[nightkrawler]

i guess i have been scared a bit by the "CHECK YOUR OIL PUMP NUT" posts, etc. i love my car and do have mods done to it, and i just dont want something to happen to it. im all for preventative maintenence if i can do it. ie, i put the stifffer 320i trans mounts in, i checked the rear diff bolt to make sure it didn't start backing out. i have 120k on her and the bolt was fine. i just dont have the resources to do the op nut. if i did, i would do it also. im no expert on the money shift prob. but i thought that it mainly occured when the car is in a turn and the trans shifts, causing your grab for 4th to actually grab 2nd. correct me if im wrong, but that seems more like a mechanical error than a driver error.

edit- when you say, turn off engine. are you referring to post money shift, or the op nut coming off?

[paul e]

>>I hate reading these threads . I dont have a hoist and im really lazy. Well I guess when I have the broken car i'll wish i did it<<

ME TOO..... I feel nauseous

[adsingl]

I was speaking of oil pump nut. Your oil light will come on, (supposing the sensor circuit is operating properly, and I've not heard of them failing to come on), and as the pressure switch is rated at .3 - .5 bar (about 4.5 - 7.3 lbs pressure), if this happens at speed (versus idle) you've almost certainly lost ALL oil pressure, in which case you'll damage your crank and/or it's bearings in a few minutes tops, cam bearing surfaces shortly after, then piston walls, assuming it hasn't already locked up, if you continued.
I drove for 2 minutes to get off the expressway, which I'd never do again, and got VERY lucky I had no damage. Get to the shoulder/safety, and turn it off, hopefully in less than 30 seconds. If you're in a situation you can turn it off right away and not jeopardize your safety, then do that. EG, don't try to make it home, or see if it will maybe go off, but I wouldn't do a "crazy Ivan" turn and wreck or cause one either. There is some film left a short while after pressure is gone, so get it shut down as soon as is safe and your engine should be ok if this was all that was going on.
ADS

[paul e]

>>Or, read Mr. Turner's letter about this same problem on Roundel.
He may know a thing or two more than you.<<

Great.. now.. how bout a reference, issue, or link??

[Balthazarr]

That additional qt probably comes in handy at this point also.
When this happens I would expect it's best to ease off on the gas while moving to the shoulder if on the fwy.
By no means increase speed unless absolutely necessary to get out of the way of other traffic.

[Balthazarr]

>>Or, read Mr. Turner's letter about this same problem on Roundel.
He may know a thing or two more than you.<<

Great.. now.. how bout a reference, issue, or link??

December 2003 Tech section.
Thsi was discussed briefly early in the thread.
Posts 66-69

[paul e]

>>December 2003 Tech section.
Thsi was discussed briefly early in the thread.
Posts 66-69<<

Ok.. thanks much.

[nightkrawler]

well, that puts my mind at ease a bit. only prob is that when on the highway or whatnot, you tend to get into a "trance" sometimes. meaning your cruising at a steady speed, keeping with the flow of traffic, maybe a fantasy or 2 about some supermodel, you get the picture, lol. and you might easily overlook a warning light on the console, till it's too late. i could have swore i heard somewhere about setting up an audible alarm to alert you to something. wish i could remember exactly. but that would be the way to go for the paranoid, like me. then again, it might take more time to do that than to just do the fix. guess i'll try to get into the habit of looking at the cluster more often.

[adsingl]

yep, there's a way to hook the oil pressure sensor into chimes.
See unofficialbmw.com - Ron Stygar's stuff.
ADS

[///M4life]

ill be checking mine on my new motor when it comes in.!!! good thread

[slcook54]

yep, there's a way to hook the oil pressure sensor into chimes.
See unofficialbmw.com - Ron Stygar's stuff.
ADS
ADS, that is also what I initially suggested, but again that doesn't guarantee that damage won't be done.

[Balthazarr]

After seeing what that annunciator looks like when I took the bolster off a while back, I think the
Stygar mod is a relatively easy way to alert oneself when in a trance while driving.