Terrible leak from valve cover?

EarlyPorsche · 04-14-2006, 12:12 PM

So I have this TERRIBLE leak from the valve cover area. Its coming from the lower valve cover seam. I tried bending the cover a bit which made it even worse. Could I double up on valve cover gaskets?

jpamental · jpamental's Garage

I don't know if that would help - but you could add some 'gasket goop' in addition to the gasket you have. The best thing to do would likely be to buy a decent used valve cover from someplace like Easy or Parts Heaven. Probably not necessary to try to find a new one. Then order a set of nice valve cover gaskets with the metal core - they don't need the gasket sealant to stay in place.

Then when you put it on, just work the valve cover around a little bit to seat it well and your leaks should be gone.

One other question though - what oil/wt are you using? If it's too thin (like a 10-40 or something) it will probably leak anyway. If so, change the oil to a good 20-50 like Castrol GTX or something. That alone eliminated a lot of leaks in my engine.

Jason

EarlyPorsche · 04-14-2006, 05:15 PM

Good point on the oil. I don't know what weight is in there because the previous owner put it in but I added a full bottle of that super thick honey like stop leak

so it should be about 900wt! But I will change that all out and put in some 15W40 or 20W50 when I get a new valve cover. At this point its just pouring out!

Duke · 04-15-2006, 02:21 PM

Sounds like your gasket is shot.

Green 912 · 06:36 PM

Flatten and true up the cover seal face and use a good quality gasket. Bending the cover will likely not help and goop might work but can also end up in places where is is not wanted.
as was said the recomended gasket is more expensive than the all cork type but worth every penny. It has a thin steel backbone sandwiched in the center of two cork layers. This type will outlast the standard all cork gaskets 5 to 1 and does not need to be glued to the cover which is worth it right there.

Easy way to true a cover is to tap hammer it over a old head with the gasket removed. Gently tap any bent areas flat but don't pound on the metal as you can expand it and the cover will warp for good.

Jeff Winter · 04-18-2006, 08:13 AM

I know this may be obvious to most of us.................

Make sure you didn`t get the gaskets on wrong...........believe it or not I`ve seen the gaskets placed on backwards.

I always use Permatex Ultra Copper silicone sealer........this stuff is without a doubt the BEST. I have zero leakage.

I`m also assumming that your leak is NOT comming from up above ( head breather etc ) and leaking down the covers making you think it`s the V/C.
Good Luck, Jeff Rallye/Sport

lep · 06-04-2006, 07:56 PM

If you have used goop, permatex, and have hammered the old valve covers, then I would buy new valve covers and start over. I use cork gaskets, and haven't had any valve cover leaks on my 912 for 26 years. 356 Enterprises ( http://www.356enterprises.com/EngineRebuild.html) sells sets of cork gaskets for $15.

djdsc · 06-05-2006, 08:33 AM

While all of the suggestions are great, especially using the gaskets with the metal reinforcing insert, the majority of valve cover leaking is from the gasket slipping during installation. It is not necessary to use heavy gasket cement on the cover or the head. A light coating of 3M trim adhesive on the gasket and the cover will provide enough tack to keep the gasket from slipping and it is easy to clean off with solvent or lacquer thinner when changing out the next time.

Once the cover bale is snapped into place move the cover around a bit to seat it into place.