Overheating 4.6 in Santa Barbara
 

I've rehabilitated a 96 4.6 RR in the past few months - coil springs, shocks, tie rods, alternator, air conditioning, window regulator, etc. It mysteriously overheated (bubbling from overflow tank) after uneventful 100 mile freeway trip. Took it to East-West in Santa Barbara, he found the thermostat was jammed open with a rod, surmised it had overheated before and pronounced the engine dead (it is still running reasonably well and hasn't overheated again). Need advice and/or a local mechanic I can get a 2nd opinion from. Not satisfied with this diagnosis.

RE: Overheating 4.6 in Santa Barbara
 

I would like to due a block test on your engine, this checks for C02 gasses in the coolant system with a special fluid. if i do confirm C02 in the coolant system (exhaust gasses) than (A) the exhaust gases are bypassing the headgaskets (replace) or (B) the exhaust gases are bypassing the cylinder liner sleeve (aka dropped sleeve/liner) unfortunately the only way to tell between the two is remove the heads after confirming the C02 gases in the coolant. if its a dropped sleeve then its engine block replacement. santa barbara auto group will charge you one one hour to perform a block test, and i can give you your 2nd opinon.