engine and drivetrain Another valve guide/seal question

[ChrisN]

I'm about to R&R my head and have determined (with FAQer help) that my valve guides & seals are gone. There is lots of smoke on decel and none on accel, compression is good also.

What I'm unsure of is how grey smoke from a cold engine is diagnosed. This pic is from my just-started '76 that is idling in a heated garage. Smoke at idle decreases as engine temp rises. Is this also a symptom of guides/seals?

Thanks!

[esty]

oil is running past the bad seals when you turn the car off, into the combustion chamber...when you start it, it's burning that oil

[Harv]

That sound's like the culprit. It also could be a small amount of coolant that has leaked from a crack when the motor is cold.

As you said, you are going to R&R the head. Make sure the machine shop pressure tests the head and also magnifluxs it too to look for cracks. I would also use the late 320i or 318i valve guids and teflon seals. They seem to last a long time.

John

[POP3Y3]

a temporary solution so that you do not get smoke is to release pressure right after you turn the car off after driving it. do so by opening radiator cap half way and let the pressure out. more than likely you will not have any smoke the next time you start it. kind of a pain in the butt but it worked for me.

[Ray_73Turkis_OH]

Thanks for the great photo and question.

Since mine is intermittent I think it might be the head gasket.

Car runs great so I am not too worried.

[Mike Self]

exhaust. Once the engine has warmed up a little (all cold engines spit out moisture until the exhaust system has warmed up), hold a piece of Kleenex or a paper towel over the exhaust pipe. If it gets damp and disintegrates, you most likely have a coolant leak. If not, it's oil smoke. Also, antifreeze exhaust smells a little sweetish, and oil in the exhaust smells like, uh, burning oil.

mike