Valve Covers Leaking?

vesnyder · vesnyder's Garage

My car has sat longer than at any other time in it's life (at least since I've had it?) and it is leaking from the drivers side valve cover. I had the valves adjusted about a year ago, so it has not been that long since the gaskets have been replaced.

Last year I had the catalytic converter heat up so much it was red hot and baked the paint on the car. Could this have warped the valve cover and this is what is causing the leakage? I saw where Wayne suggests in 101 Projects to have the valve covers remachined flat. Anybody ever done this and has it solved leaky valve cover problems?

Lothar · Lothar's Garage

You wouldn't be running synthetic oil, by any chance?

Run the car and the oil leak will probably disappear. This happened to me with a car that had a complete top to bottom rebuild within 4000 miles. With synthetic, those damned tiny little molecules can find their way past just about anything.

Since running the car more regularly, I have seen not a drop of oil anywhere.

s_wilwerding · s_wilwerding's Garage

If you don't have turbo lower valve covers, buy some. Also, when you change the valve covers, use new silicon-beaded gaskets available from our host. I had oil seeping out of my lower valve covers until I used the new gaskets - doesn't leak a drop now.

vesnyder · vesnyder's Garage

When I bough the car it was not leaking a drop, but I am using synthetic and it has been leaking ever since.

I do have the turbo valve covers. I am going to remove them to ensure they are flat. If not I will have them machined. I will also try non-synthetic oil next time!

Early_S_Man · 11:43 AM

If the aluminum Turbo covers are still flat and you have been using the green silicone-beaded graphited gaskets ... then you are probably overtightening them!

The torque spec has been very low -- lower than the M6 sump cover nuts -- at 8 Nm, about 5.8 lb-ft, since 31 March 1981! A 1/4" drive torque wrench is needed to accurately measure the toque. In a pinch you can use a 13 mm combination wrench with your hand as close as possible to the nut -- one hand only, just the four fingers of your right hand to tighten, and it won't be too tight.

Superman · 12-09-2002, 04:45 PM

If the valve cover is not flat, just find someone with a big, table-mounted belt sander. JW placed mine on his, and it made them flat. Time required to straighten all four: about one minute.