M3 E36 possibly need valve job?

[MommasM3]

Hi folks,


I'm pretty new to the forum but have done a lot of reading on here over the past year. My wife has a 95 M3 E36 with the S50 (I think? It has the long tube intake manifold) with about 190,000 miles on it. It has been a great car and a lot of fun up until about the last year. I would appreciate a little advice and direction if anyone wouldnt mind sharing their expertise and familiarity with this car. Hope this post isnt too long, but I will try to add as much info as possible.


Symptoms - About a year ago the M wouldnt pass emissions and started burning oil. It also had the typical marbles in a can rattle from the Vanos. So we replaced the vanos, replaced the cats, and after about 3 tries on inspection, it still was burning oil, enough to where we could see white smoke vapor out the tail pipe with a flashlight. replacing the Vanos did seem to wake the motor up quite a bit, but we still werent passing EMs.


After a few months we developed what I would describe as valve tick. Increases/Decreases with RPM, and from the stethescope soulds like it was coming from under the valve cover. Oddly you can hear it under the car as well, which made me hope it wasnt rod knock. Soo...we parked it until we decided what to do as the mechanic said it probably needs a valve job, but wouldnt know until he tore it apart, and $4k just to start.


This past weekend, I got the itch again to get the car running, and started with a compression test. Dry, with the plugs out, thottle open, cylinders were 210 - 215psi all the way across. With a little oil dropped in they were 240-255 all the way across. I noticed something on #4 tho...every so many revolutions it would not compress and the guage would hang, and then it would kick back in. Didnt happen every time, but usually 2 out of 8 revolutions it would skip. This had me thinking that the #4 valves may not be seating all the way, possible causing the valve tick, and if it was sticking...the oil burn. or maybe failing lifters...Also, #4 spark plug was very dirty/oily.


Reading up, I came across a lot of posts about a cyclone oil separator issues causing oil burn, dirty valves, etc so I started looking for that. I've pulled the air box, MAF, TB, plugs, coils, fuel rail, injectors, and intake thinking I'm probably going to need a head, and to see what shape it was all in. Intake runners have some oil in it. Most of them are dry, but #4 and #5 are kind of oily. I absolutely can not find anything on this car that looks like the cyclone oil separator...so maybe it doesnt have one?


Thats where I got to last night, and before I finish pulling the head, I was hoping someone might input based on the info above.


Am I looking in the wrong place for this separator? Are there any other things I should be checking first before going the re-man head route?


Thanks a bunch!

-Phil

[DrewMontE36]

A 95 will not have the cyclone oil separator, only 96-99 models have them.

As for your oil consumption problem, you could check the inside of your manifold/valve cover breather hose to see how much oil is being pulled into the intake. A little is acceptable, but if it's puddles then that could indicate excessive blow by meaning you'd be looking at a head job.

[RRSperry]

You need to find a more reasonable mechanic. $4K to start? The total job should cost $2K if nothing is bad in the head. If you have to start replacing valves, guides, and lifters, it can get expensive.

For $4K you can buy a much lower mileage engine and have it installed, and motor on....

[284Shooter]

What oil are you running? When is the last time you changed it?

Those compression numbers are fantastic. A little too fantastic for 190k, so I'd say if you are getting between 190-210 per that head has likely been off already and probably what you are hearing is a collapsing/plugged lifter or one of your spark plugs is loose.

EDIT:

White smoke is either condensation or coolant. First is nothing, 2nd is bad. Do a combustion gas test to the coolant. Oil burns blue~ish out the tailpipe.

How quickly does the oil level drop? Are you getting the cats DAMN hot before you take the car through testing. What is it failing? HC level?

[MommasM3]

Thank you for the replies!


What oil are you running? When is the last time you changed it?

I believe we are running castrol Full syn 5w30. Mech changed it recently. My wife is religious with the changes. It would burn enough that by the time oilchange time came around (3000) we would have added a quart or 2.


Those compression numbers are fantastic. A little too fantastic for 190k, so I'd say if you are getting between 190-210 per that head has likely been off already and probably what you are hearing is a collapsing/plugged lifter or one of your spark plugs is loose.

I agree. We did the test with two separate test guages just to be sure. The head hasnt been off since she owned it, but she bought it used 5-6 years ago so maybe the PO did a head job.


White smoke is either condensation or coolant. First is nothing, 2nd is bad. Do a combustion gas test to the coolant. Oil burns blue~ish out the tailpipe.

How quickly does the oil level drop? Are you getting the cats DAMN hot before you take the car through testing. What is it failing? HC level?

Yes, she would call the Emissions place and make sure they could take her right away, and then run higher RPM for about 20 miles and nearly drive it straight on the rack.

I grabbed some pics last night of the intakes. Looks like:

#1 - Clean/Dry

http://i1022.photobucket.com/albums/af346/philmay75/M3/int-vlv3_zps2bdc4ac6.jpg (http://s1022.photobucket.com/user/philmay75/media/M3/int-vlv3_zps2bdc4ac6.jpg.html)
#2 - Dirty

http://i1022.photobucket.com/albums/af346/philmay75/M3/int-vlv2_zpseee68114.jpg (http://s1022.photobucket.com/user/philmay75/media/M3/int-vlv2_zpseee68114.jpg.html)

#3 - Clean/Dry
http://i1022.photobucket.com/albums/af346/philmay75/M3/int-vlv3_zps2bdc4ac6.jpg (http://s1022.photobucket.com/user/philmay75/media/M3/int-vlv3_zps2bdc4ac6.jpg.html)

#4 - Very Dirty
http://i1022.photobucket.com/albums/af346/philmay75/M3/int-vlv4_zps5b7ed1fb.jpg (http://s1022.photobucket.com/user/philmay75/media/M3/int-vlv4_zps5b7ed1fb.jpg.html)

#5 - Dirty
http://i1022.photobucket.com/albums/af346/philmay75/M3/int-vlv5_zpsaee5458a.jpg (http://s1022.photobucket.com/user/philmay75/media/M3/int-vlv5_zpsaee5458a.jpg.html)

#6 - Dryish but a little dirty
http://i1022.photobucket.com/albums/af346/philmay75/M3/int-vlv6_zps64ff3864.jpg (http://s1022.photobucket.com/user/philmay75/media/M3/int-vlv6_zps64ff3864.jpg.html)

The intake manifold had a small pool (very small) of oil just outside the breather hose.

- - - Updated - - -

and yes, it failed on HCs and NOX

1st EM
Low RPM HC 129 Fail
Low RPM NOx 1737 Fail

2nd EM
Low RPM HC 172 Fail
Low RPM NOx 3470 Fail
High RPM NOx 848 Fail

3rd EM
Low RPM HC 255 Fail
Low RPM NOx 927 Pass
High RPM NOx 848 1444 Fail
High RPM HC 168 Fail

[rajicase]

What Im gonna respond to is the 4k head/valve job. If you've pulled the intake manifold, you can do the head. I pulled my head and honestly found the intake manifold to be the biggest pain in the ass part of the job. From where you are, the valve cover, vanos, sprockets, secondary timing chain and tensioners need to be removed, along with some sensors and hoses, then pull the head and do the cams on a work bench along with the exhaust. You can rent the special tools needed for next to nothing, take the head to a machine shop and have this entire job done for ~1k.

[MommasM3]

What Im gonna respond to is the 4k head/valve job. If you've pulled the intake manifold, you can do the head. I pulled my head and honestly found the intake manifold to be the biggest pain in the ass part of the job. From where you are, the valve cover, vanos, sprockets, secondary timing chain and tensioners need to be removed, along with some sensors and hoses, then pull the head and do the cams on a work bench along with the exhaust. You can rent the special tools needed for next to nothing, take the head to a machine shop and have this entire job done for ~1k.


Thanks for the vote of confidence, Rajicase,

Yes, we are planning to do it ourselves at this point. (and yes, the intake is a PitA) Since my post, I've pulled the valve cover, fan, shroud, radiator, hoses, etc. All I have left is headers, vanos, sprockets, tensioners, and the sensors, as you mention. I'll probably also pull the cams and replace the lifters. I guess if my wife's mech had said he'd do it for 1500 - 2k, I'd have let him do it, just because it will be parked longer with me doing it. But the $4k price tag as a minimum for a head job got me motivated. We did the vanos and knock sensors ourselves last year, so some of this came off much easier this time. But honestly, I'm a rookie mechanic so I've been taking it slow and asking for a lot of advice.

I mainly wanted to make sure (with my original post) that folks more experienced than myself agree that this sounds like a head/valve job issue, before I tackle what's left. Thanks again!

[ScotcH]

Oil blowby is really only caused by a few things: valve seals, valve guides, or rings. As your compression numbers are very good, I would not suspect rings at this point, so the bottom end is likely prefectly fine. Pull the head, and have it rebuilt ... that should only cost ~$500, including new seals and a valve job and shave. Guides usually don't need to be done, but have them check for excessive play. Get a Goetze or Elring head gasket (stay away from Victor Rinez), obviously new head bolts. Other than that, it's not a bad job. Headers are probably the most PITA part of the job.

[MommasM3]

Thanks for the replies, folks. I got the head off and as others have said, it wasnt that bad of a job. Didnt have to pull the headers to get the head out, so that made it easier...heavy, but easier. Here's a few pics of the piston tops and bottom of the heads.

http://i1022.photobucket.com/albums/af346/philmay75/M3/null_zps8b639e44.jpg (http://s1022.photobucket.com/user/philmay75/media/M3/null_zps8b639e44.jpg.html)

http://i1022.photobucket.com/albums/af346/philmay75/M3/null_zpsdc55c29f.jpg (http://s1022.photobucket.com/user/philmay75/media/M3/null_zpsdc55c29f.jpg.html)

http://i1022.photobucket.com/albums/af346/philmay75/M3/null_zps831b05f5.jpg (http://s1022.photobucket.com/user/philmay75/media/M3/null_zps831b05f5.jpg.html)

http://i1022.photobucket.com/albums/af346/philmay75/M3/null_zps7658d537.jpg (http://s1022.photobucket.com/user/philmay75/media/M3/null_zps7658d537.jpg.html)

http://i1022.photobucket.com/albums/af346/philmay75/M3/null_zpsce86e812.jpg (http://s1022.photobucket.com/user/philmay75/media/M3/null_zpsce86e812.jpg.html)

One interesting thing is that according to the bentley guide, and a few videos I've watched on this, someone timed the cams at exactly 180 degrees off. Instead of the lobes on Cyl 1 pointing to each other at Crank TDC, the lobes on cyl 6 point to each other. Only thing I can figure is that the camshaft position sensor adjusted for this.

http://i1022.photobucket.com/albums/af346/philmay75/M3/null_zps1bf6ef6b.jpg (http://s1022.photobucket.com/user/philmay75/media/M3/null_zps1bf6ef6b.jpg.html)

The cyls still have cross-hatch and no vertical scoring marks, so still hoping rings are fine. Now off to the machine shop to get the valves done. :)

[ScotcH]

No, you're just at the exhaust stroke TDC instead of the compression stroke TDC. When you reassemble it, put the cams in the right place (it cyl 1 pointing at each other)

[MommasM3]

No, you're just at the exhaust stroke TDC instead of the compression stroke TDC. When you reassemble it, put the cams in the right place (it cyl 1 pointing at each other)

I get your point, as Cyl 1 and 6 move together, so essentially you just skip the first half of the firing order, but something would have to tell Cyl 6 to fire at Crank TDC instead of firing Cyl 1, right? Since both Crank and cam have a position sensor.

[ScotcH]

I get your point, as Cyl 1 and 6 move together, so essentially you just skip the first half of the firing order, but something would have to tell Cyl 6 to fire at Crank TDC instead of firing Cyl 1, right? Since both Crank and cam have a position sensor.

Yes, something does ... the cam sensor. Otherwise it would fire on both storkes (and does, when in limp mode I think when the cam position sensor dies). So anyway, just pointing out that noone installed the cam wrong ... you just didn't put the engine at TDC for cyl 1 (you put it at TDC for cyl 6)

[MommasM3]

Gotcha...Maybe we are saying the same thing. I set it by the crank mark "0 I T" and set the flywheel lock pin. I thought that was TDC for #1, but the way it was installed, it was TDC for #6. At the very least it doesnt matter, other than the fact that if you time it with the cams at 180o you cant remove the chain guide, because the triangular end of the intake cam blocks that long screw from being removed. :nono

[ScotcH]

Gotcha...Maybe we are saying the same thing. I set it by the crank mark "0 I T" and set the flywheel lock pin. I thought that was TDC for #1, but the way it was installed, it was TDC for #6. At the very least it doesnt matter, other than the fact that if you time it with the cams at 180o you cant remove the chain guide, because the triangular end of the intake cam blocks that long screw from being removed. :nono

We're not saying the same thing. When you put it to the mark, you had it at TDC cyl 6. You should have rotated it another 360º, then you would have been at cyl 1 TDC, and cams would have been in the correct place for head removal :) No one timed it wrong ... you just had it wrong when you set the lock pin

[MommasM3]

Doh! I get it now. 4-stroke passes TDC crank mark twice. Ima dumbass and I should probably take this car to a professional. Lmao.

[fun2drive]

By the way VR owns Elring as of a couple years ago so it doesn't matter much which one you use for a head gasket.
One thing is critical with this install and prep and that is the RA value of the head. RA meaning roughness average which is how smooth the head needs to be. BMW specs state 50 or less. You machine shop if they know jack will know what you are talking about. The only VR gaskets I have ever seen fail was because they tore not blew and that is caused because the head was not smooth enough. Remember aluminum expands 3 times as much as steel and that movement rips the gasket if it can't slide some.
Your pistons look fine for 190K miles and yes the cross hatch still being there is pretty normal on BMW engines. I have seen the cross hatch still there when well past 270K miles on other S52 M3s so they do build a good engine.

Really important point here.
While you have this thing apart STRONGLY suggest you replace the heater hoses you can't get to when the intake and head are on as well as your starter unless it is already replaced. If you have not drained and refilled your power steering ATF now is the time. Doing these things will save you a lot of your own time and money later down the road...

[ScotcH]

By the way VR owns Elring as of a couple years ago so it doesn't matter much which one you use for a head gasket.
One thing is critical with this install and prep and that is the RA value of the head. RA meaning roughness average which is how smooth the head needs to be. BMW specs state 50 or less. You machine shop if they know jack will know what you are talking about. The only VR gaskets I have ever seen fail was because they tore not blew and that is caused because the head was not smooth enough. Remember aluminum expands 3 times as much as steel and that movement rips the gasket if it can't slide some.
Your pistons look fine for 190K miles and yes the cross hatch still being there is pretty normal on BMW engines. I have seen the cross hatch still there when well past 270K miles on other S52 M3s so they do build a good engine.

Really important point here.
While you have this thing apart STRONGLY suggest you replace the heater hoses you can't get to when the intake and head are on as well as your starter unless it is already replaced. If you have not drained and refilled your power steering ATF now is the time. Doing these things will save you a lot of your own time and money later down the road...

Good advice, but just because a company owns another, does not mean they gaskets will be the same (I don't know this ... I'm only sayin', know what I'm sayin'?). In any case, I would use Goetze. Have used those on all our iron block builds with no issues.

[MommasM3]

Thanks for the input! I'll definitely look at adding heater hoses to the growing list of new parts to change while in there. I picked my pride off the floor, dusted it off, and the head is off to the shop as of this morning for a bath, shave and new shoes. Before I finished removing the head, I did a leakdown with no cams. Granted the motor was cold, but I just wanted to see where it was at, especially with #4 skipping on the compression the way it did. Here's the results:

Tested @90psi for 3 minutes, TDC on each cyl, using a dual gauge tester:



Cyl Psi %lost Leak from
1 80 11 Intake


2 89 1 Exhaust


3 80 11 Intake


4 70 22 Both


5 90 0 -


6 78 13 Exh