Valve Cover Gasket Blow-Out?????

[knife13]

I've got a 97 cobra running 8psi with a v2. Today on the dyno my drivers side valve cover gasket blew out the side (literally see it hanging out the side) spilling oil everywhere. The blow out seemed to happen at high RPM (not sure if it was when he let off or not). There is a Steeda oil separator on the drivers side between the stock grey plastic pcv valve and the intake manifold. On the passenger side there is a hose from the valve cover to a catch can with another hose going to the non-boost side of the intake piping. Any ideas what could have caused the blowout? I had the compression tested at the local garage that is replacing my valve cover gaskets and it came up good.

I was thinking that one of the catch cans is plugged up or maybe the bypass valve isn't working?

 

[coposrv]

How old is the valve cover gasket? Is the oil separator sealed? If not I could see the pressure from the intake going through the separator and pressurizing enough to blow out an older gasket. Is your PVC have a check valve?

 

[coposrv]

The way it's set up looks like it wouldn't need a check valve but maybe for some insurance.

 

[knife13]

I'm guessing the gaskets were the original ones. The steeda separator is sealed. Same with the catch can on the passenger side. There isn't any type of valve on the passenger side, just a couple hoses. The Drivers' side has that stock plastic check valve that pushes into the valve cover. The car is still at the shop getting the valve cover gaskets replaced, I can take a few pics when i get it back.

 

[racebronco2]

I don't see how the gasket can blow out unless it wasn't installed correctly. I have to admit it installed a valve cover before and the gasket wasn't in the groove all the way. Rushing to get the gasket replaced on a hot engine wasn't the best time to replace it.

 

[hasty]

I don't like to bear bad news, but I'd say there's a good chance you have a cracked piston or ring and it's pressurizing the crankcase under boost. I could be wrong, but that's what my first assumption would be.

You might try putting a breather on both valve covers temporarily though. If it's not smoking out the exhaust it may be a crank ventilation issue.

 

[knife13]

Appreciate the input. It looks like the gasket had been leaking for a while, there was a ton of gunk on the drivers side of the k-member. I'd like to think that there is no cracked piston or ring (I just had the compression checked). Is there a way compression could come up OK and a piston still be cracked? There is a good amount of smoke coming out of the vents on both valve covers.

 

[coposrv]

If the compression test came up ok then I highly doubt anything in the rings or pistons we're the cause of the gasket blow out. It was probably just old.

 

[knife13]

It seems like there is a bit of pressure in the crankcase when i pull the PCV out of the valve cover. Is this normal?

 

[slowassgt]

put some breathers on there

 

[Shaunk]

Did they do a leakdown test? We had one come thru the shop a few years ago that would block out valve cover gaskets under boost. It had blowbye issues. It did have a catch can set up with -8 lines and still would do it.

 

[knife13]

Don't think they did a leakdown. The guy told me each cly was just over 150 for compression. This car has 42k miles on it btw. Could the plastic PCV be bad?

 

[coposrv]

Put breathers on it and see if it pushes the gaskets again. Try to narrow down the problem.

 

[96snake719]

I had the same issue... put a set of breathers on there and haven't had a problem since!!!

 

[knife13]

Sooo little update

The car has developed a crazy dead miss when cold, but when its warm it doesn't happen. Also, from the looks of it I can see a bit of oil/coolant between the head and where the IMRC mounts to it on the drivers side (not sure if this is related). If I take the oil cap off while its running, there is a steady stream of white smoke that comes out. The car also puts white smoke out of the exhaust every once in a while on start-up and while its idling. The temp on the stock gauge also seems to creep while i'm sitting still. I checked the plugs over the weekend and they all looked normal except for 6 and 7, they were black and covered with oil. I was leaning towards the head gasket being shot on that side. The car was also down about a quart of oil. Could the head gasket be slightly leaking? Or does it sound like something far worse (aka a cracked head)?

 

[jasonmark1993]

Most likely cause is you lifted the head a little/blew head gasket, but you could be right and broke something. Won't know until it comes apart.

 

[coposrv]

Most likely cause is you lifted the head a little/blew head gasket, but you could be right and broke something. Won't know until it comes apart.

Exactly this.

 

[shadowmach]

My car had white smoke somtimes to it ended up being a dropped valve seat on cyl. 7 and had misfires on cyl. 7 & 8

 

[phillipmach1]

I had the same problem under boost and i instal a check valve and problem solve.

 

[itSSlow98]

I had the same issue, blew two valve cover gaskets and it was due to blowby and ended with 4 broken pistons. I hate to say it but you NEED to do a leakdown and that will telly ou right there where your issue is. It will tell you if its the rings, pistons, valves, or head gaskets or none of the above. I do think you will find the reason though.