I am new to the XJ6 and have been reading about the head gaskets issues and block cracking. I am not new to troublesome engines with head gasket issues, 2004 Land Rover Discovery 2 4.6 V8.

https://www.cometic.com/applications...aguar/xj6/1985


If the "normal" head gaskets don't last long has anyone considered and or tried a Cometic Multi-Layer Steel (MLS)gasket? Sure, they are not inexpensive and from my research primarily designed for engines that are taken apart and put back together often, but if they last it may be worth the price.

An added benefit of the MLS gasket is they can be had in many bore sizes and multiple thicknesses.

 

I've used the MLS gaskets on several 6 cylinder engines and they are great. No leaks, no need for retorquing. The custom thicknesses are a lifesaver for cars with 9:1 pistons that have had a generous amount of metal taken off the block and/or head to ensure the compression doesn't get too high.

 

Good feedback Jagboi64.

Were any of the engines in a Jag and if so, did you not have any further issues? I asked the same question about the use of MLS head gaskets on my Land Rover forum where they fail at probably a 100% rate but got no feedback.

I think a lot of people may be put off by the price. Why buy a head gasket that costs $250.00 when you can get a Payen gasket right now on sale at Moss Motors for $27.89. BJ020 GASKET, head, Payen brand | Moss Motors

 

I've used 3 of them so far, all on Jaguar engines. No failures yet. The big reason to use one for me was to bring the compression down. The XK engine (especially in 3.8 form) doesn't like compression over about 9.2 or you get detonation.

I had one where so much metal had been taken off the block that the compression with a standard gasket would have been about 10.5. Using a custom thickness MLS gasket I was able to bring it down to 8.8. Without that gasket the block would have been unusable, and the owner wanted to keep the car matching numbers.

 

Sounds like they are worth the price. I was going to ask about the use of a copper spray, but this video answered my question.