Smoking problem: Fixed

[D Unit]

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[X5only]

Planning to tackle the smoke issue this weekend. Here's additional info I found in my searches:

545i Blue smoke after idle, Valve seals? - Page 6 - Bimmerfest - BMW Forums

See post #146.

[stiubhartach]

Good post in #146. I agree with him and disagree with the follow up posters who claim to be BMW techs. I've known some terrible techs who were just glorified parts changers and didn't understand systems at all. Valve stem seals do fail, but CCV vacuum leaks are more common and far cheaper to fix. Remember as you diagnose ,that residual oil in the manifold and hoses will take a while to clean out.

Don't drive the car with a plugged CCV system. The crank case needs vented to the outside air to allow blowby to escape. The intake manifold hose port can be plugged indefinitely.

I fixed an old Alfa Spider I owned by putting a catch can in the equivalent vent line. I just manually drained it once in a while.

Good hunting!

[X5only]

Originally Posted by stiubhartach

Good post in #146. I agree with him and disagree with the follow up posters who claim to be BMW techs. I've known some terrible techs who were just glorified parts changers and didn't understand systems at all. Valve stem seals do fail, but CCV vacuum leaks are more common and far cheaper to fix. Remember as you diagnose ,that residual oil in the manifold and hoses will take a while to clean out.

Don't drive the car with a plugged CCV system. The crank case needs vented to the outside air to allow blowby to escape. The intake manifold hose port can be plugged indefinitely.

I fixed an old Alfa Spider I owned by putting a catch can in the equivalent vent line. I just manually drained it once in a while.

Good hunting!

To clarify, which ports do you mean can be plugged during diagnosis - red arrow or green arrow?

[stiubhartach]

Red arrows must be plugged or you get a vacuum leak which messes up the mixture. Green arrows need to be open, or vented to allow pressure that escapes by the rings into the crankcase to escape. Normally it gets sucked into the intake ( red arrows) and burned in the cylinders.

[X5only]

Originally Posted by stiubhartach

Red arrows must be plugged or you get a vacuum leak which messes up the mixture. Green arrows need to be open, or vented to allow pressure that escapes by the rings into the crankcase to escape. Normally it gets sucked into the intake ( red arrows) and burned in the cylinders.

Got it, thanks!

[X5only]

Ok, smoke test done by Indy came out negative- no vacuum leaks. Further, my diagnosis shows that the car still smokes after unplugging the pcv hoses and sealing intake manifold ports. I idled for around 20 minutes then revved until smoking stopped, idled again and repeated the process multiple times with the same results- heavy blue-white smoke. So this proves that the valve stem seals is the source of the oil and not the CCV system.

[stiubhartach]

It does appear to be valve stems seals for you. Did you do a visual inspection inside the intake manifold for oil? It's 4 bolts to remove the throttle body. Don't lose the bolts! They are very hard to find replacements for.

[X5only]

Originally Posted by stiubhartach

It does appear to be valve stems seals for you. Did you do a visual inspection inside the intake manifold for oil? It's 4 bolts to remove the throttle body. Don't lose the bolts! They are very hard to find replacements for.

Ok, the driver side pipe has oil, passenger side doesn't- so points to oil being sucked through it implying a vacuum leak somewhere? The other perplexing thing is that there's absolutely no oil on any of my spark plugs! If it were leaking valve stem seals, wouldn't they be fouled?

[stiubhartach]

It definitely looks like oil in the pipe. That's what mine looked like on the drivers side also. That points to good news.

The other thread talked of only a couple plugs being fouled by valve stem seals due to uneven failure rate of the seals. If they all look similar it points to other causes. Also good news for you.

Keep up the search!