Oil In The Intake Path ('94 Es 300)

Jeff 94 ES300 · April 25, 2006

I just pulled the air filter box and the intake hose off my ES300 (totally stock.) I found a lot of oil in the intake hose (from the filter to the throttle body.) Why would this happen? I think I know where it is coming from - small hose from the top of the engine over to the middle of this intake hose. But I don't konw what it means.

Actually, I guess it means the EGR or PCV valve are shot. But that's my shade-tree, I don't know jack about emissions control systems, opinion. Can someone educate me? Also, I assume my intake track is now nicely coated in oil/junk. Any advice for cleaning upstream components?

I can tell you my car has about 100k miles, it's sluggish accelerating and that's why I started this little project.

Thanks,

Jeff

Toysrme · April 25, 2006

There are 2 blow-by/crankcase vents.

1) The open breather from the front valve cover to the intake pipe (Between the TB & MAF)

2) The PCV valve on the rear valve cover that feeds the intake manifold directly

Unless you run a catch can, filter it, or take the valve cover off & fix the fact that it can suck up trace amounts of oil - you'll always have a bit of oil in the intake manifold. The oil isn't a rael problem, the huge amounts of carbon build-up is a problem. :)