Blow-by popping rubber plugs out of head

[2rich2thin]

Hi Forum
1999 Porsche Carrera with 3.4 watercooled boxer 6 cylinder engine non turbo with 6 speed manual.
We just changed both head gaskets and the engine runs fine, except there is blowby on the drivers side head that pops out the rubber plugs that cover the ends of the camshafts.
There is no mention of a PCV valve in the manual. There is a "secondary air check valve. Is this the PCV valve? There is a plastic pipe on the side of each head that I suspect sucks the pressure ized vapor and mixes it with intake air as in a PCV on most cars. With the engine reinstalled it's not possible to pull these and check for vaccuum. Your thoughts on the cause of this blowby and the remedy?

PS I've been told valve guides but the car ran fine before blowing the head gasket. Thanks for your input.

[JFP in PA]

Originally Posted by 2rich2thin

Hi Forum
1999 Porsche Carrera with 3.4 watercooled boxer 6 cylinder engine non turbo with 6 speed manual.
We just changed both head gaskets and the engine runs fine, except there is blowby on the drivers side head that pops out the rubber plugs that cover the ends of the camshafts.
There is no mention of a PCV valve in the manual. There is a "secondary air check valve. Is this the PCV valve? There is a plastic pipe on the side of each head that I suspect sucks the pressure ized vapor and mixes it with intake air as in a PCV on most cars. With the engine reinstalled it's not possible to pull these and check for vaccuum. Your thoughts on the cause of this blowby and the remedy?

PS I've been told valve guides but the car ran fine before blowing the head gasket. Thanks for your input.

First of all, the most common reason that the green cam plugs pop out is excessive use of sealer on the cam covers. There also should be no sealer used on the green plugs.

Porsche uses a odd term for what is a PCV valve, which is on the engine end of the hose that connects to the AOS unit. Item #6 below:

[txhokie4life]

What JFP says.

Sometimes you can clean out the area near the plug without pulling the valve cover, however
often times sealant has clogged one of the oil routes and it diverts to the green plugs.

My mechanic did this several times until I beat him upside the head a few times
and he learned less is more when it comes to sealant.

m

[2rich2thin]

Thank you for that information. I was aware that you are not supposed to use sealer on the plugs but I sure did use too much sealant on the driver's side cover which is the one blowing out plugs. They sure do have tiny little channels that I could have sealed off. So we will drop the engine again. Thanks so much gentlemen!

[BYprodriver]

Originally Posted by 2rich2thin

Thank you for that information. I was aware that you are not supposed to use sealer on the plugs but I sure did use too much sealant on the driver's side cover which is the one blowing out plugs. They sure do have tiny little channels that I could have sealed off. So we will drop the engine again. Thanks so much gentlemen!

FYI these engines Never have problems with the head gaskets!

If you are losing coolant it may be a cracked head which is common after water pump failures.

[txhokie4life]

Originally Posted by 2rich2thin

Thank you for that information. I was aware that you are not supposed to use sealer on the plugs but I sure did use too much sealant on the driver's side cover which is the one blowing out plugs. They sure do have tiny little channels that I could have sealed off. So we will drop the engine again. Thanks so much gentlemen!

You can change the valve cover with the engine in the car.

not easy but maybe easier than dropping engine.

m