wrd1972

I was playing around today and held the engine at red-line (5800 RPM) in second gear for a few seconds and then nailed it to get an idea of how much punch it had at this engine speed. I did this twice.

I got back to the house and noticed a small amount of oil spray on the passenger side valve cover. It ran down a burned a bit on the header.

It was not a great amount of oil.

It appears that it came out around the big plastic tube where you pour the oil in the engine. The tube does not screw into the valve cover very tight so I dont trust the seal.

Obviously when I was doing this pressure built up enough in the engine to possible blow some oil out.

I have a brand new PCV valve. I have noticed a little bit of oil in the throttle body that traveled through the rubber hose, but not great amounts.

Is there somthing I need to check to ensure the engine is ventilating properly?
Why does this happen?Thanks

Injuneer

You already identified one possible cause.... plugged PCV valve. You also identifed the problem with the fill tube. The threads strip and it doesn't hold tight enough to the valve cover for the o-ring on the bottom to seal tight.

Replace the PCV valve first. After you do that, pull the oil cap off with the engine running and feel over the fill tube for vapor puffing out, or listen for it with your ear near the opening. If you can feel vapor puffing out, it might indicate that you are getting excessive blowby on the rings, more than the PCV valve can handle.

But when that happens, the pressure should be prevented from building up by the flow in the air supply tube reversing, and the vapor flowing back toward the throttle body. That's when the oil gets into the line, and will eventually puddle on the top of the TB (under the plastic cover) and start to drip down into the TB/intake manifold. Its normal to get a little bit of oil in the system if you spend a lot fo time at WOT (there's no vacuum to pull the vapor through the PCV valve at WOT) but if there's a lot of oil reaching the TB, it could be another sign of excessive blowby.

wrd1972

Injuneer,
Took the cap off and dont feel any kind of vapor or puffing coming out.

I did buy the filter cap thing to attach to the hose to try to minimize the oil on the TB.
This appears to only be an issue at heavy WOT.

This problem occured with the new PCV. Blowby at this time does not appear to be an issue.

The oil filler neck does have that stripped feel to it, I might be able to RTV it in the cover.

Based on this does this sound like the "normal" thing that happens at WOT.
Thanks

ABA383

If the threads on the tube are shot you can get a new filler tube from GM for like $7.00 and it comes with thread sealer on the threads...fits in very tight...no leaks...I just did this a few months ago....

--Alan

Loadre

Or ditch the tube and just use a cap. There's a lot of oil up in the valvetrain at those RPMS so if you were up there for a while then you were probably just throwing a lot out the oil filler.

wrd1972

I cap is fine with me. What kind of cap would fit?

Loadre

Go to advance/autozone and they'll have one.

92/95TransAm

i used the cap off the top of the filler neck. basically just remove the filler neck and put the cap in the hole. fixed my problem