I hope this doesn't happen to anyone here who's running the Mitsubishi 2.6 NA engine, but it happened to me. Engine was running normally, began missing continuously on one cylinder. began losing other cyls almost immediately until engine died and wouldn't restart. Had truck towed home, pulled sparkplugs and three of them looked like they had been hit with a hammer. Pulled head and found it had dropped a valve seat. Pieces had migrated to three cylinders with some chunks embedded into top of piston. Good news is, I was able to get salvage head and after installation truck ran well even though some cylinder scoring had occurred.

What do you expect, we are dealing with 25-30 year old trucks. If this was a new truck than I would be concerned but after 30 year things fail. I would say the engine has had a pretty good go of it. Long story short, if you want to avoid these types of failures in the future you may need to upgrade to a high end rebuild or go with a vehicle that is newer than 25 years old. Over the years the Mitsubishi G54B has proven to be a reliable engine. It was one of the most commonly used engines in the 1980's. I have owned several and never had an issue.

Cheese, I'd have the radiator rodded out. A dropped seat is a sign of chronic overheating...

Glad to hear things came out ok. Ditto what FE said. If it's an automatic, also check that the transmission isn't the cause of the overheating ((assuming the auto cools itself via the engine radiator like the v6 models). <img src="/forums/images/graemlins/kewl.gif" alt="" />