Bottom oil pan gasket & breather 2004 c5z

[froggy47]

My tech & I went all over the engine today & conclude that the bottom oil pan cover is leaking all the way around only at high rpm. It has not been hit & all the bolts are spec.

The dye is thick & evident there and just seeps out from there. The top of the front composite spring is dry & bottom wet & wet on the pan surface.

I am 98% sure this is the area & we will put on a new gasket soon.

Any special procedure on the gasket, dry or gasket maker? Tighten like a head bolt sequence?

The other thing is 100% of the guys that I talk to that run hard, say a breather or an oil catch can will help the problem of oil leaks, they say extended running at high rpm is the cause & none of them leak much if at all if you drive "normal" .

I know this is ouside GM specs, but I need to try it anyway, any suggestions on this? Maybe I need to open the pcv hole to relieve more pressure? Is the pcv on newer engines a different spec? LS3/7/9?

:)

[c4c5specialist]

Hi there,

All GM Corvette PCV systems are validated at high RPM TRACK CONDITIONS.

There is no modifications that should be made.

I have track cars at LIME ROCK that are oil tight after YEARS of race track running.

The thoughts that you NEED a catch can are simply ludicrous. Check your PCV valve first. Your 04 has the latest updated PCV system and has proven track ready.

Install all GASKETS per GM FSM.

Allthebest, c4c5

[froggy47]

Thanks.

When I find a prefectly good gasket that leaks, I try to find the underlying cause. Does anyone know where the primary venting/relief for the crankcase pressure (high rpm) happens?

One guy says (on my motor) it's a vent off the pass side valve cover that goes into the TB. This is separate from the pcv that goes from the valley cover to the TB.

Is this true? He says it is more than just the PCV.

That HOSE looks fine. How would I test to see if it vents crankcase pressure at high rpm? Is there a pressure "valve" on this system that could hang up?

I don't want to replace a good gasket with another good gasket & still have a leak.

:)