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JFairman JFairman is offline
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Join Date: Jul 2006
Location: S. Florida
Posts: 7,208
Ken is talking about replacing valve guides and you're talking about replacing valve stem seals - two different things.

The valve guide is the the bronze alloy guide that is pressed into the cylinder head and then the the valve is inserted into it.
Head has to come off to replace it and the valve seal can be replaced with the head on the motor after the spring retainer and spring have been removed.

You linked to pictures of the exhaust valve ports. The guides and oil leakage around them don't look bad compared to most of them on 911 turbo's that have some miles on them and there is absolutely no correlation between exhaust valve ports and oil in the turbo's steel intake pipe or aluminum charge pipe.
If the exhaust valve seal and guide leak oil into the exhaust ports it gets partially burned during the exhaust stroke and blown through the exhaust headers, hot side or turbine side of the turbocharger, through the muffler and out the exhaust.

Oil leaking there will be likely from when the motor sits for a while after running and the engine case, oil return tubes and bottom section of the cam towers where the exhaust valve stems are fill up with oil and if the seals and guides are worn it can seep into the exhaust ports.
When the engine is running there is positive exhaust pressure in the ports and it would blow any excessive oil in the clearance between the valve stem and valve guide back up the valve stem past the valve seal and into the cam tower.

Oil in the intake pipe and airflow meter like you have is likely coming from the oil tank breather hose and that usually points to over filled engine oil level, or worn piston rings, piston ring lands, cylinder walls, or broken piston rings from excessive detonation and the resulting combustion blowby carrying oil mist into the crankacse breather hose and if it's eventually connected to the air cleaner housing like it origonally is it gets recycled into the air intake leaving oil film on everything in it's path.

You're better off asking motor questions with pictures like this on the engine rebuilding forum... there will be more accurate and helpful replies and fewer guesses there.

Check the oil level while the motor is hot and idleing, and do a compression and leakdown test.
Old 09-07-2011, 07:36 AM
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