Smoking sometimes, looking for ideas...

[951Dreams]

2001 740IL, 4.4L 171K miles.

On cold start I'm often seeing smoke, the car is new to me and it often goes away really quickly but it seems like it's oil to me (blue/gray). I also sometimes see it when accelerating from a stop. Almost always after I've been idling for a bit. Like a drive through, or a parking lot.

I'm about 95% sure I've got vacuum leaks (I'll have another post about that). I also know my valve cover gasket is shot (leaking oil). I have a plan for all that. But I need some input on the smoking issue, I simply don't know these engines yet.

From my symptoms, I call valve stem seals as my number one suspect. For those more familiar with these, does that sound reasonable? If indeed that is my problem, can they be replaced without taking the heads off? I know on some cars you can suspend the valves with compressed air and replace the seals. Is that possible with these?

Are these prone to leaking oil other ways into the intake? I'm planning a total top end gasket job (Head gaskets aside), any chance that will solve my smoking issue? I'll learn these and all their ins and outs, but right now I'm a total noob, so school me please!

[Timm]

That is classic PCV failure symptoms - have a read of these:

http://www.meeknet.co.uk/e31/BMW_M60...entilation.htm

http://www.meeknet.co.uk/E32/PCV/Index.htm

[Sundaycruzer]

2001 740IL, 4.4L 171K miles.

On cold start I'm often seeing smoke, the car is new to me and it often goes away really quickly but it seems like it's oil to me (blue/gray). I also sometimes see it when accelerating from a stop. Almost always after I've been idling for a bit. Like a drive through, or a parking lot.

I'm about 95% sure I've got vacuum leaks (I'll have another post about that). I also know my valve cover gasket is shot (leaking oil). I have a plan for all that. But I need some input on the smoking issue, I simply don't know these engines yet.

From my symptoms, I call valve stem seals as my number one suspect. For those more familiar with these, does that sound reasonable? If indeed that is my problem, can they be replaced without taking the heads off? I know on some cars you can suspend the valves with compressed air and replace the seals. Is that possible with these?

Are these prone to leaking oil other ways into the intake? I'm planning a total top end gasket job (Head gaskets aside), any chance that will solve my smoking issue? I'll learn these and all their ins and outs, but right now I'm a total noob, so school me please!

If your lucky it’s just the pcv on back of intake, but I would prepare to do timing guides because most of the time it’s the oil separator. Which is located behind guides.

[georgebest]

I had the same issue and it was the PCV (or as BMW calls the CCV), $30 fix but hard to make it without removing the intake manifold but certainly possible.

[armiller1]

I had the same issue and it was the PCV (or as BMW calls the CCV), $30 fix but hard to make it without removing the intake manifold but certainly possible.

You can get in there. I did it, albeit about 5 years ago, but I did it. My hands aren’t massive, but they’re bigger than most.

Get a micro driver set like this one:

https://rover.ebay.com/rover/0/0/0?m...2F190836532421

I use mine ALL the time.


Sent from my iPhone using Tapatalk

[georgebest]

You can get in there. I did it, albeit about 5 years ago, but I did it. My hands aren’t massive, but they’re bigger than most.

Get a micro driver set like this one:

https://rover.ebay.com/rover/0/0/0?m...2F190836532421

I use mine ALL the time.


Sent from my iPhone using Tapatalk

Real man tears apart the whole car, removes intake manifold and turns a 20 minutes job into ten hours!
Just kidding, certainly better just to replace it from the back. Nice kit, thanks!

[951Dreams]

Real man tears apart the whole car, removes intake manifold and turns a 20 minutes job into ten hours!

I think I'm going to be doing this anyway! I need new valve cover gaskets, so I'm thinking of pulling the intake and doing every gasket along the way. I figure with 170k on the clock, and 18 years of aging, it's about time. Might as well do it now while I'm still in love with the car!!! LOL

I'm going to try to replace everything that's replaceable while I'm in there. I'm hoping I won't have to crack another cover for 100k more miles that way. I'll just pray the head gaskets make it that much longer. How do the HG's hold up on these while we're talking about gaskets???

Thanks for all the input guys! I really am thankful for the help!

[georgebest]

I think I'm going to be doing this anyway! I need new valve cover gaskets, so I'm thinking of pulling the intake and doing every gasket along the way. I figure with 170k on the clock, and 18 years of aging, it's about time. Might as well do it now while I'm still in love with the car!!! LOL

I'm going to try to replace everything that's replaceable while I'm in there. I'm hoping I won't have to crack another cover for 100k more miles that way. I'll just pray the head gaskets make it that much longer. How do the HG's hold up on these while we're talking about gaskets???

Thanks for all the input guys! I really am thankful for the help!

I have never seen anybody complaining about HG so I assume they are holding up well

Good luck, that's what I did a month ago...before realizing that TCG should be replaced as well. If you planned to do that it probably makes sense to do it at the same time.

[951Dreams]

Good luck, that's what I did a month ago...before realizing that TCG should be replaced as well. If you planned to do that it probably makes sense to do it at the same time.

Yeah, I've got that in the plan. I haven't researched exactly what all that might involve. But I figure it can't be too much extra work if you already have the intake off. And I'm betting it's never been done. Rather get it out of the way now.

[cyclops2]

I have never seen anybody complaining about HG so I assume they are holding up well

Good luck, that's what I did a month ago...before realizing that TCG should be replaced as well. If you planned to do that it probably makes sense to do it at the same time.

This was my slippery slope. started out to replace the CCV and couldn't get 1 bolt out. So out came the intake. With intake out, I figured, might as well do the VC. Now you are staring at the valley pan and you figured, better get after it while you are there.

then it starts to hit you, the TCGs will fail, so should I do them now while the engine is apart. this will eat at you until, you succumb and begin digging in deeper.

it starts adding up quick, but if you truly want to keep the car and want it to last another year... you'll need to add the TCG and Vanos to the list.

George did the job very quickly, only a month..........mine is still apart after 5 years!! lol

Welcome to the forum! we all have the same affliction....AND LOVE IT!

[Faymett]

If your lucky it’s just the pcv on back of intake, but I would prepare to do timing guides because most of the time it’s the oil separator. Which is located behind guides.

If you change out the oil separator should you also update the timing chain?

[robo740il]

Replace the chains if you like, but the timing chain guides are what fail. Since you have to remove the lower timing cover to get to the OSV, you definitely want to replace the guides too.

[Faymett]

Replace the chains if you like, but the timing chain guides are what fail. Since you have to remove the lower timing cover to get to the OSV, you definitely want to replace the guides too.

I've seen some videos where people do some type of bypass of the whole ccv system with a "Catch can" reroute. Are you familiar with these and can they be done on the 740il?

[clarkitect]

If you replace the CCV (back of intake) and it still smokes it could be that the OSV (behind timing chain) is clogged with sludge. This can be cleaned out by removing the oil pan and flushing it out with some kerosene. Works like a champ.

You can do a catch can as well, but I'd try the flush method first.

[Sundaycruzer]

If you change out the oil separator should you also update the timing chain?

Yup no brainer, depends on year but rebuild vanos also
Edit: replace pcv on back of manifold first

[951Dreams]

Without me having to dig through a bunch of threads to find a good one, does anyone have a saved link to a good writeup of what needs to be done with the VANOS? Mine seems fine, but while I'm in there....

[clarkitect]

http://beisansystems.com/procedures/..._procedure.htm

There you go.

[georgebest]

This was my slippery slope. started out to replace the CCV and couldn't get 1 bolt out. So out came the intake. With intake out, I figured, might as well do the VC. Now you are staring at the valley pan and you figured, better get after it while you are there.

then it starts to hit you, the TCGs will fail, so should I do them now while the engine is apart. this will eat at you until, you succumb and begin digging in deeper.

it starts adding up quick, but if you truly want to keep the car and want it to last another year... you'll need to add the TCG and Vanos to the list.

George did the job very quickly, only a month..........mine is still apart after 5 years!! lol

Welcome to the forum! we all have the same affliction....AND LOVE IT!

LOL! I did the job "quickly" but not sure if "properly"
Yes, it is really a slippery slope. I think the key is to have all tools and parts ready when you start it. Shouldnt take too long then, e.g. a stupid teflon ring on VANOS was holding me up for two weeks. Otherwise would have been done on two weekends plus one day.

But I seriously think the best is to do it all at once. Much more efficient time wise, only downside if you screw up something, harder to figure what went wrong.

- - - Updated - - -

Without me having to dig through a bunch of threads to find a good one, does anyone have a saved link to a good writeup of what needs to be done with the VANOS? Mine seems fine, but while I'm in there....

As linked above, Beisan is the best to start. Raj is a gentleman. But if any of your VANOS units are off center or has cracked plastic inside (you won't know either by just looking at it) you won't be able to put on the teflon ring. I guess it's not an issue 90% of the cases, but I run into it on one unit.

[951Dreams]

HOLY SMOKE!!!!

Yeah..... I think I'll just stick with the intake/valve cover gaskets with CCV for now..... and gaskets for everything associated. I had no idea changing the chain guides and OSV required removing the chains. I might take a peek at the upper guides just to be sure they aren't toast yet, but since I have no VANOS symptoms I think I'll hold off at least till next year. I've already got a Porsche torn apart to that level, I don't need a BMW to boot.

Thanks for the input guys! You guys are great!

[georgebest]

But best is to drop the oil pan and check there, half an hour job and can save your engine.

[clarkitect]

If you drop the oil pan make sure the osv drain is not plugged. This will cause smoking on start up due to BMW’s infatuation with absurdly long oil change intervals. Run some string trimmer line up it and flush with kerosene.

https://www.bimmerforums.com/forum/s...4#post29901964

[951Dreams]

But best is to drop the oil pan and check there, half an hour job and can save your engine.

Check the OSV you mean? I was thinking I'd do the CCV and valve cover gaskets and if it's still smoking the OSV was next to check.

From what I understand the OSV is just a glorified vortex canister that spins the incoming air to separate the heavy oil from the gasses. Then the oil drips back in the pan and the gasses go on to get sucked back into the intake. There isn't anything inside to "break" right? It can just get clogged. Or is there more to it I don't know about??

But your right, I guess fixing a bad CCV without addressing a clogged OSV is kinda spinning your wheels. Is the idea that with the OSV clogged it's just going to not feed any air through the circuit and that crankcase air, oil and all, just goes back into the intake? And the intake becomes a makeshift OSV filling with oil? Then it gets sucked into the combustion chamber on a cold start causing smoke??

Sorry, just trying to understand this setup. My Acura Legend had a similar convoluted setup, way too over engineered. It would get clogged and cause a bad mix on the rear cylinders that led to pinging and head gasket issues. Or so the story goes. Nothing like that in these right? Just smoke?

[georgebest]

I was referring to checking TCG by suggesting to drop the oil pan.
On CCV vs OSV: CCV is an easy fix, costs you approx $30 and it goes bad often. When my car was smoking it was the CCV, I'm almost certain that is your issue as well. Probably takes 30 minutes to install tl if you dont have too large hands. It's 6-8 small torx bolts if I recall correctly, basically you unscrew and screw it back. This can give you an idea: https://www.newtis.info/tisv2/a/en/e...nifold/2VQQzs7
Problem with OSV is that it's probably a harder job, though Clarkitech's kerozin method above is quite brilliant. I would personally fix CCV first and see what happens.

[951Dreams]

I was referring to checking TCG by suggesting to drop the oil pan

It took me a minute... Lower Timing Chain Guide!!! Got ya!!!! Good idea!!! I've got a CCV ordered, valve cover gaskets ordered, MAF/TB gaskets ordered, and all intake gaskets ordered. I'm hoping that will solve my smoking and stalling on cold start/miss/ruff idle till warm issue. All my problems scream vacuum, so I'm sealing it all up!!!

Thanks george for the great idea! And thanks clark for the OSV clean out idea. I think you posted it on my other tread too, but if I drop the oil pan I'm doing both for sure!!!

[R Shaffner]

When the timing chain guides failed on my '97 540, the pieces that broke off were all from the center section, in the V. I'm pretty sure visual inspection wouldn't have told me much in advance. The chain wears groves in the plastic. That's a function of rpm, mileage, and lubrication. If you bought the car used and don't know whether the guides have been changed or not, a close inspection might tell you. (No grooves vs. distinct grooves.) But the pieces of plastic that wear and break off will be those under stress, and those are hard to see with the chain on. (When the pieces come off, you'll know.)

My '97 540 went 230,000 miles and that OSV never clogged. I had to replace the CCV just once. That might be because the oil specified for that car was 15W-40 Rotella. That's right, dino oil for diesel engines. Did all those diesel detergents help the OSV stay clear? I don't know. Might have. The shorter change intervals almost certainly helped too. (When I replaced the guides after 170,000, I didn't replace the OSV because I didn't know to. It still never clogged.)

After that car got totaled I bought an '02 with 150,000 miles. It burned oil pretty badly and had a blown CCV. I replaced the CCV and it promptly blew again. The problem was the OSV was completely clogged, so instead of separating oil from the by-pass air it basically added oil to it. Like an oil carburetor. I wasn't ready to do the guides, and wasn't confident that sticking something up the OSV tube from the crankcase would clean the OSV enough to keep it clean for long. So I added an external OSV, using one made for the X5 with the same engine. Works like a charm. Hasn't burned any oil since. (On that car, the new CCV would work, and not blow, only after fixing the OSV issue.)

Good luck!