This is an addition to this thread.

https://www.thirdgen.org/techbb2/sho...hreadid=308342

Heres the new information. I took one of the runners off and found a small puddle of oil where the runner meets the intake manifold. Also there is a moist layer of oily carbon on the inside of the runners and plenum. There is also oil coating the inside of the throttle body after the throttle blades. There is some oil in both pcv lines that run above the valve covers. Any information on the engine can be found in the link above. I am using a quart of oil about every 200 miles. What is going on here? Obviously the oil is entering the engine right near the throttle blades. I guess the oil has to be comming from the pcv line over the passenger valve cover? How else could it get to the throttle blades?

Thanks for the help
John

 

I did not read the old thread... Sorry, but, have you replaced your PCV valve lately? If it is stuck, or simply the wrong flow rate, you would see these kinds of problems.

 

Yes the pcv valve has been replaced, several times. That is the first thing i thought of. This isn't a tired old engine it has 4000 miles on it. But thanks.

 

If you are getting oil into the throttle body, I would think PCV is about the only source that could provide it. (well, it's not like I have never been wrong before..... LOL) You may want to simply block off the PCV, and drive the car for a few days, and see if that makes any difference.

The only other thing I could think of would be an internal vacuum leak at the manifold/head. But, I dont beleive that would explain the oil in the TB.

A quart every 200 miles is quite excessive for a motor that young. What else have you tried?

 

That be the problem. The rings have been replaced once since the rebuild. But i wouldn't doubt that my engine builders screwed up the rings twice. The pcv valve has been replaced. All info on the engine and a more detailed description of the oil consumption can be found in the other thread above. The valve seals were replaced during the rebuild. A high volume or high pressure oil pump was installed, i don't remember which off hand. Another one of the things my engine boys put on that i didn't want.

 

I vote for leakage past the intake manifold gaskets.

As for "...i noticed a SMALL pubble of oil on the outside of the intake manifold near where the runners meat the manifold", that's from intake manifold mount bolts not being coated with thread sealant.

I've seen both on different engines.

 

That was my vote too on the other thread.

 

Yeah guys i know what you are saying but that doesn't explain oil inside the runners and throttle body and plenum, right?

As a side note, the intake bolts were coated. But you never know, maybe they worked loose a little and let some oil up.

 

Yes, it does explain it. Don't fall into the trap of thinking air only moves one way in an intake manifold.

 

hmmm, excellent point. But does it make it all the way back up to the throttle blades? Maybe it could i suppose.

 

ttt