I disassembled my intake system today to check for air leaks, as my car has been idling a bit rough. I was surprised to find a good deal of oil coating the inside of the intake plumbing up to at least the throttle body, with oil on the air flow sensor plate and saturating one side of the air filter under the sensor plate. The screen above the plate also had a good deal of oil on it. Can someone give me an idea of what's gone wrong here? TIA.
Oil In Intake
Oct 19, 2004
4 Replies
This is normal and typical. I found the same in my '91 GTI. This comes in through the PCV valve atop the valve cover.
Jim B.
My car has a splashguard. I don't recall having this much oil on the air filter in the past, so it really got my attention. What is the mechanism by which leaking valve guides contribute to oil in the intake syatem? If my valve guides (or seals) were bad, wouldn't I be burning oil too? The car never smokes and I rarely need to add oil between changes.
Combustion pressure leaks past valves and guides increasing crankcase pressure.
My hose had a restrictor plug in it. Does yours?
My car never smokes but I have found that Mobil 1 does not smoke even when you have an engine that burns oil.
What k>My car has a splashguard. I don't recall having this much oil on the air
Jim B.
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