Regular repair shop tried 3 times to stop my valve cover leak. Not until they used gaskets from Jaguar did they stop the leak (so-far). They said the gaskets from Jaguar were thicker, than the ones from their supplier. Perhaps, useful info if you get a leak

 

More than likely they finally decided not to screw it up again.

 

No issues with my fel-pro gaskets, but if I remember correctly torque setting and correct inside-out torque sequence is key!

 

A man of few words, always worth waiting for!

 

I have run into the same issue before. Some aftermarket sealing kits just dont seem to be as thick. With the valve cover properly tightened, I found that I could actually "move" the cover after fitting.

 

The reason is there was a change of valve cover around 2000 which used thinner seals even though they looked identicle, these will be no good on earlier cars.

When the 4.2 came out the covers were changed again to a different type/look