Diversion of an original post here:
https://www.jaguarforums.com/forum/x...ailure-114241/

99 KX8 with the heads off for low compression and SUSPECTED head gasket failure... Beginning inspection of the heads revealed leaking exhaust valves in a few cylinders... Water filled port leak test here on Youtube:

Removal of the valve revealed a clump of debris on the seat and valve faces... It LOOKS like aluminum, but was fairly soft, and easily removed with a fingernail... I have about 1/2 the exhaust valves showing this leakage, and they DIRECTLY correspond to the worst compression holes... That's not a surprise, but the figures I obtained cannot be totally due to the small leak at the seat... i.e. this particular hole tested at 30 psi compression...

Car has 60k, heads completely done 10k ago for overheat and dropped seat.... Heads pulled this time for major compression loss... Now suspect the misfires in the holes with leaking valves to have caused cylinder wash leading to very low compression...

ANYBODY SEE this before??? The crap on the seats in particular...

THANKS FOR LOOKING!!!!!!!