Originally Posted by Karl

Just to give a quick run down on the problems found so that anyone using a cometic gasket in future can double check this!

After I had rebuilt the engine using a cometic gasket the first thing I did was refill the coolant system. After I had filled it I noticed water leaking down the block. Upon inspection its was coming from the side of the head gasket.

Thus I stripped the engine again and indentations were found in the head face and block. Upon examining the gasket it was found that the seperate fire rings that sit in the middle of the 3 layers were slightly larger in diameter than the cut out in the middle layer!!!! This was causing the fire ring to sit slightly proud and thus hold the head up enough to leak. However it damaged the head and block in the process.

It's not an easy fault to spot and I didnt before fitting it even though I visually checked the gasket over. The three layers are quite loose and thus I doubt I would spot the fault again until the head is torqued down!! Unless you actually pull the outer layers apart to view the centre layer and fire rings its almost impossible to detect! (And its not a good thing to start pulling the steel layers apart with a new gasket!!)

Thus everyone BEWARE!!!!

As a summary I pulled the engine out machined both the block and head faces and rebuilt with a genuine Mountune gasket! Its now 100% perfect again no thanks to Cometic!!

Hope this small bit of info may save someone elses engine, allthough it does seem to be a rare fault!!