I replaced the whole pcv and oil serpator box and I still ahve puffing from the dipstick tube. I cleaned out both holes on the engine they were restricted. Replaced all hoses (and the fuel pressure regulator while I had the rail off). I cleaned the manifold fully with engine cleaner and degreaser. I rinsed it all off dried it put all back together. I cleaned the egr hole and valve. Cleaned the throttle body. Removed the screen on the flame trap.


The strange thing is after driving 10 mins the puffing is gone. Unless I pull off the oil filler cap and it is back again.

I suspect I have a vacuum leak only when the car first starts up and then once driving it goes away. Anyone know what could cause this?

Any thoughts would be appreaciated.
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1988 245 340,000 Kms , 1990 740 GLE 16V 220,000 Kms

Hello,


How many kilometers are on the 850?

It may be time for a rering. Verify with compression readings.


Goatman

Hi, once up on the time I had a leaking air inlet manifold gasket, it went worse when engine was warming up.
Thus i would first check possible leaks around the gasket by spraying water when the engine is still runnig cold and the leak letting air in.
br tapsa