M30B35 Valve Stem Seals

[dcardenas]

I recently picked up a 535i/5 and it's got a bit of blue smoke coming out of the tailpipe and a burning oil smell to go with it. I haven't had a chance to start digging around in there yet but I picked up a new valve cover gasket (and a bunch of other maintenance parts)and I'm hoping that will do the trick.

Anyway, might be a noobish question. Are valve stem seals a common problem on the M30B35? I've been searching A LOT and really don't see much info (if any) on tackling this job for our motors.

Is there anything else that could be letting that oil getting into the combustion chamber?

[Layne]

It's not really worth doing unless you're rebuilding the whole engine.

[zubbie]

M30's leak like old men with prostate problems. The most common places are valve cover gasket, the notorious water pump bolt through the timing chain cover, the timing chain cover gasket, pan gasket and Jesus nut seal.

oil coming from the tailpipe is not likely to be any gasket or seal. Check spark plugs for oil deposits. Oil is either coming from below (rings) or above (valve guides, etc). Sometimes PCV issues can suck oil in but I don't remember that being a problem for an M30.

[demetk]

My m30 at 225k miles must not be that old yet. How do you perform a proctoscopy on one these anyway?

[nonturbodan]

Do an oil change with 20w50. If that doesn't do anything you either have worn or carbon fouled rings or leaky valve seals.

[Ricky318i]

It's not really worth doing unless you're rebuilding the whole engine.
I did mine, but it was part of a head rebuild. It's such a mission to get the valves out, that you might as well just do everything else while the head is off... Skim head, new gaskets of course, coolant swap and clean inlet and exhaust ports, etc.

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[Layne]

I did mine, but it was part of a head rebuild. It's such a mission to get the valves out, that you might as well just do everything else while the head is off... Skim head, new gaskets of course, coolant swap and clean inlet and exhaust ports, etc.

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Well I mean there is a technique to do valve seals with the head still on, but I don't see how it's worth it. Oil is spewing everywhere by that point, makes no sense to put a lot of effort into one small part.

FWIW though, valve seal smoke is most noticeable if you close the throttle at high RPM's (high engine vacuum sucks more oil in). Look in the mirror when you let off the gas and see if the smoke suddenly increases.