Hey,whats up?
Do any of you boosted guys have problem with oil coming out of the air/oil separator?When i put my charger back on the other day,i took it for a hard run on the highway.When i pulled over and popped my hood to check things out,my intake manifold was covered with oil.I have a breather filter on the end of the hose,and it sits right on top of the intake manifold.When i took the filter off and started the car,there was air blowing out of it,is that normal?I have a feeling that the piston rings may be worn causing blowby.Would anything else cause this?Im gonna try and do a leak down test tommorow after work.Im pretty pissed because i rebuilt this motor 2 years ago.This sucks because i have a dyno appointment this monday.If the rings are leaking,its not gonna put down good numbers.The car does feel strong though.
Peter
'06 Cobalt ss/sc W/G85 Package
Gm Stage II W/2.79" Pulley
K&N Drop In Filter
Custom Magnaflow Dual Exhaust
No,i had to add oil because it was low.
Peter
'06 Cobalt ss/sc W/G85 Package
Gm Stage II W/2.79" Pulley
K&N Drop In Filter
Custom Magnaflow Dual Exhaust
I dont wanna say it but it *might* be a broken piston head (top ring land) allowing the air to go past the pistons and into the crank case. Keep us updated.
-Aaron
www.TurboTechRacing.com
Performance Parts For Cavalier, Sunfire, Cobalts and More!!!
Shifted wrote:The valve in the air/oil seperator box might be stuck open, they are expensive though 
There is no "valve" it is just a plastic baffle that allows the oil to seperate from the air, before going to the intake.
-Aaron
www.TurboTechRacing.com
Performance Parts For Cavalier, Sunfire, Cobalts and More!!!
I dont think there is a valve in the separator box.I took it off not too long ago and there is nothing inside of it.
I hope the piston aint broken.When i was running with out the s/c,i didnt have any problems with oil coming out of the hose.
Peter
'06 Cobalt ss/sc W/G85 Package
Gm Stage II W/2.79" Pulley
K&N Drop In Filter
Custom Magnaflow Dual Exhaust
Do you have a compression tester? Check how even it is cylinder to cylinder. If it off more then 10+ % difference you might wanna think more about a piston.
-Aaron
www.TurboTechRacing.com
Performance Parts For Cavalier, Sunfire, Cobalts and More!!!
Shifted wrote:You didn't overfill your oil did you?
Say what?!?!???
It sounds to me like you have excessive crank case pressure building up. It could be caused by a couple of things. You piston rings could be toast letting lots of blow-by into the crank case and pressurizing it. Or it could be boost going threw your PCV in yout intake manifold building the crank case pressure. I'm willing to bet the problem is with the PCV.
- 93 mph in the 1/8 mile
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I have access to a compression tester at work.Ill probably do that and a leak down test.I took my plugs out yesterday and there was no damage to them.If something broke off the piston it would hit the spark plug right?
Peter
'06 Cobalt ss/sc W/G85 Package
Gm Stage II W/2.79" Pulley
K&N Drop In Filter
Custom Magnaflow Dual Exhaust
Might have hit the electrode may have not. If it was a chunk of pistons it might have went out the exhaust valve without any notice.
-Aaron
www.TurboTechRacing.com
Performance Parts For Cavalier, Sunfire, Cobalts and More!!!
top ring lands gone!!!! join the crowd i had the same issue 2 cylinders had the top ring land gone oil was spraying everywhere out the dipstick out the pcv valve(air/oil seperator i think you called it) but yeah shes toast
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On boosted 2.4's, I advise plugging the hole in the head found behind the intake manifold. That will keep you from aplying positive pressure to the air/oil seperator...... And/Or install a catch can, and run the hose from the cam cover to that...... (I'd also plug the hole in the head then, since you wont be using the air/oil seperator)
I'm going to lean towards blow by. Might not be messed up pistons, but deff. sounds like blow by.
SPD RCR Z -
'02 Z24 420whp
SLO GOAT -
'04 GTO 305whp
W41 BOI -
'78 Buick Opel Isuzu W41 Swap
I had the same thing.
Piston ring or something stupid like that, you got blowed!!! Blow by. It is what it is.
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Well i did a compression test today.All 4 clyinders were 200 psi.So,i guess my rings are good.Maybe the breather filter is clogged with oil,and when i get on it,it just blows it out.Im gonna clean out the filter and see if i get a little less oil build up on the intake manifold.Thank your for your suggestions.
Peter
'06 Cobalt ss/sc W/G85 Package
Gm Stage II W/2.79" Pulley
K&N Drop In Filter
Custom Magnaflow Dual Exhaust
pretty decent compression, thats good....... did you do a leak down test as well? That will give you an idea to how well the rings seal.
SPD RCR Z -
'02 Z24 420whp
SLO GOAT -
'04 GTO 305whp
W41 BOI -
'78 Buick Opel Isuzu W41 Swap
no,i didnt do a leak down test.I figure since all the cylinders are putting out the same numbers,theres no need for one.If 1 of my cylinders was reading low,then i would of done one.Im just glad they put out good numbers.Im dropping off the car monday for a dyno tune,so hopefully it puts down some good numbers.I just want it to break 200.
Peter
'06 Cobalt ss/sc W/G85 Package
Gm Stage II W/2.79" Pulley
K&N Drop In Filter
Custom Magnaflow Dual Exhaust
A leak down test could show alot of things that a compression test doesn't. Burned valve for example. But a burned valve won't cause your problems. I'm gona go with Skilz though. Check the PCV Valve. Since your compression numbers are good, rings are pretty much ruled out.
It's POSSIBLE that you have a cracked block or cylinder head, but again, that would usually show up in a compression test. I say usually because it's possible, although unlikely, that you can get a crack somewhere in the intake port. Since you're boosted, the crack could lead to under the cam cover... which is part of the crankcase because of the oil return holes. Like I said, possible but unlikely. Also a worst case scenario. Not trying to scare you, just thinking of any possibility at all.
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check the pcv........ how can you check it? The Crank Case Vent is on the cam housing cover...... there is no PCV...... at least a conventional one....
go to autozone, and try to have them look one up.......
SPD RCR Z -
'02 Z24 420whp
SLO GOAT -
'04 GTO 305whp
W41 BOI -
'78 Buick Opel Isuzu W41 Swap
sounds like a good case of blow by...
I was a retard, and now I'm permanently banned.
Ok,i just thought of something.Let me know what you think.I think my bov may be adjusted too tight,and its causing compressor surge.Before whenever i let off the pedal at pretty much any rpm,i would get a nice whistle sound.Now it dont really make alot of noise.It will still blow off at higher rpm,but it doesnt seem as loud as before.What im thinking is the bov isnt opening fast enough or very little when its supposed to.Do you think its possible that compressor surge can force air into the oil return line when the throttle plate is closed,and cause positive pressure in the crankcase?Maybe this is whats causing oil to come out of the breather filter?
Peter
'06 Cobalt ss/sc W/G85 Package
Gm Stage II W/2.79" Pulley
K&N Drop In Filter
Custom Magnaflow Dual Exhaust
