Engine Mechanical problem
2002 BMW 525 6 cyl Two Wheel Drive Automatic 97000 miles
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I just recently had the Oil changed, after about a week I was at a stop light the light changed to green, as I accelerated a big puff of white blue smoke came out of the exaust. I took it to my Local Mechanic and had it looked at. They said they could not find anything wrong. It is still smoking badly, and I don't want to drive it until I find out what the problem is, I would like to know what a ring and Valve job will cost.

How is it driving same pickup good idle start good?
A well maintained BMW with 97K should not be needing such expensive work. Check all fluids are they at correct levels?
Let us know

The car does not smoke all the time at start up, but sometime it will. It idles good and even runs good. I checked the oil level and also to see if I could see any water in same, all were fine, also it seems not to smoke at constant speed only at acceleration or like I said sometimes at startup. Does this car have vacum assist shift? I have heard rumors that maybe this could be a problem, sucking transmission fluid back.

Possible valve guide seals but you say it started after oil change. Do you go to same place every change? What weight oil did they use? Also have the PCV checked this can suck oil into engine.

I have taken my car to a BMW dealer for all oil changes, they use Synthetic oil. I have thought of the pvc valve, but the shop I took it to locally said they checked that, I live 80 mi from nearest BMW dealer and was afraid to drive it there to have it checked.

We have a moderator Dr. Hagarty is the premier BMW Tech. He gets on line later in day will ask him to take on your problem.

Thanks, tell the Dr. when It smokes, i'm talking like a fogger spraying for mosquitos. Also I have heard of a bypass valve that is common for these to go bad, and cause this problem.

The smoke could well be caused by a failed cyclone separator, or as BMW calls it a "pressure regulator". The part number is 11-61-7-501-566. One additional symptom that happens is a "honking" noise from the engine, especially on deceleration or when you rev the engine slightly. This diagram may also be of help.

Thanks, I think you are on the right track. I talked to a small Auto repair place here that deals with German made cars. He also said the same thing, that is a very common problem with BMW's. He called it a exhaust relieve valve, don't know if it is the same thing.

It is fairly common for this failure and they can call it anything, a picture is worth a thousand ...........