JohnC

Let's discuss PCV system on Boosted cars...

40 posts in this topic

So @Mike pointed out I might have a leaking rear main seal.

I also noticed my passenger side valve cover is leaking oil (probably just needs tightening down more?). This could be why it looks like I have a rear mail seal leak because of how its draining down the head to block and probably blowing all over the place.

I already had a tiny leak in the oil cooler o-rings. All these early 5th gen's had that problem.

But what I think made all this crop up and the existing leaks to a way worse degree is -- boost.

Every time I get on it, once done, I smell oil.

I looked under the car and oil is everywhere.

I rolled away from the E85 pump and I seen puddles of oil where I was parked.

Checked oil, I'm still up to level.

But my oil pressure has slightly dropped at idle and part throttle driving.

I'm thinking this boost pressure is a bit high and is finding the weak links in my oil seals, causing them to leak and blow oil out under boost.

Aside from replacing the leaky seals, do I need to get a vacuum pump or vent PCV to atmosphere and re-tune?

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I was thinking your catch can would work like it was, but maybe not.  Mine has a check valve built in, apparently yours doesn't.

Two options.

1.  Re-route your catch can hose connected to the intake.  Plug the nipple on the intake and run that hose over to the air filter like the valve cover hose is.

2. Leave that hose connected to the intake, but put a check valve in it.  I think I have one that might work.

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I still need to replace those seals though right?

I assume it won't be a tiny drop over time anymore since the blower is pushing oil out like this? 

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5 minutes ago, JohnC said:

I still need to replace those seals though right?

I assume it won't be a tiny drop over time anymore since the blower is pushing oil out like this? 

I would change the catch can routing first and see.  If the crank case is seeing full boost right now, that could be the entire problem.

JohnC and Ashley P like this

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You don't need to change the whole catch can, just do one of the things in my first post.  Add a check valve or route the hose away from the intake.

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If it blew oil out of the rear main seal, do you think it's OK (popped back in place) or will it need replacing?

I'll probably need a hand with that since I don't have a check valve, etc.

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EVAP systems are often different for boosted engines, consider looking into a possible need for a check valve in that too.

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31 minutes ago, JohnC said:

If it blew oil out of the rear main seal, do you think it's OK (popped back in place) or will it need replacing?

I'll probably need a hand with that since I don't have a check valve, etc.

If it physically blew the rear main out, it will need to be replaced.  But it would be pouring oil out if it did that.

Swing by my house any time after 3:30 and we can put that check valve in.

mstrpth, JohnC and 66sprint6 like this

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I asked DBR how much boost it was making per the log and he said by his math he seen 15lbs peak. :eeek:

Is that too much or OK? :fear:

Maybe I should back down my shifts to like 6500 instead 6800?

Sent from my iPad using Tapatalk

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Well it might not be anything bad.

Looks like the valve cover gasket is pushed out and leaking pretty good.

ead05740fa67a106084eda3e15670c87.jpg

Bet that’s the main source of the oil blowing out.

Sent from my iPhone using Tapatalk

66sprint6 likes this

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10 hours ago, Tino said:

Is it easy to do valve covers on that car?

Drivers side, yes.

Passengers side sucks because all the wiring, fuel line, etc.

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Did one more WOT run to 14lbs boost to see if the valve cover gasket was the main source.

It isn't.

It's the rear main seal...

I googled and Camaro5 forum has thread after thread on leaking rear main seals, oil cooler seals and oil pan gaskets.

It's very common that early production Camaro SS like mine blow out rear main seals, especially at 10lbs of boost or more.

So there is more work to be done. :smirk:

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So...shouldn't the crankcase have a very UNrestricted vent to the atmosphere?   What's allowing pressure to build in the crankcase?

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2 hours ago, JohnC said:

Did one more WOT run to 14lbs boost to see if the valve cover gasket was the main source.

It isn't.

It's the rear main seal...

I googled and Camaro5 forum has thread after thread on leaking rear main seals, oil cooler seals and oil pan gaskets.

It's very common that early production Camaro SS like mine blow out rear main seals, especially at 10lbs of boost or more.

So there is more work to be done. :smirk:

Does the new seal do the trick or is it going to have the same issues as the factory seal?  Hate to see all this but you will get it ironed out soon enough!

Matt

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If I were a bettin' man, I'd say the seal is a symptom, not a cause.  Those seals go bad at about 150k with NA engines.  And I see no reason to ever have pressure in the crankcase whether the engine is NA or has 200 psi boost.

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Well, I think Mighty Mouse sent me the wrong bracket (thinking it was a 5th Gen ZL1), but I made it work.

I rigged my Mishimoto catch can to sit on top the MM bracket with zip ties until I can get something fabbed up. It's hooked up between the pcv valley to tb as it was originally.

Mighty Mouse can is hooked up from the oil fill cap to blower air filter.

I'm hoping that'll work.

I couldn't see any other way to hook it up as the valley pcv is where most of the trashy oil / water vapors collect.

The MM can is there just to relieve PCV pressure for me....

@Mike does it sound like I set it up right?

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I don’t think the mighty mouse can is doing anything hooked up like that.

If there isn’t a check valve between the intake and crank case, it’s pushing boost into the crank case.  That’s what I was going to put in the mm line.

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Mike, what path does his blowby take to get to atmospheric pressure?  How "big" of a vent path is needed?  (I'm looking at a stock 6.0, it's anemic, restricted through about a 5/16" elbow.)

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