Overheating 91 Legend

I have a overheating 91 legend. Everything was great eight weeks ago, just had the car detail inside out and notice a leak. i took it to the mechanic and he said no problem only transmission leak at radiator, will replace radiator and car will be fine. Well after replacing 3 leaking new radiators we finally found a brand that did not leak but now the engine overheats, coolant boils over into overflow tank. car overheats at idle, on the highway, with the heater on and sometimes it blows cold air instead of heat. the mechanic thought for sure it was the water pump so we chaged timing belt, water pump, thermostat, hoses and belts and nothing changed, the car still overheats at idle, on the highway it does not matter. Dealer says it may take hours and $110/hour to diagnose the problem and my mechanic want to replace my 233k engine with and engine with 133k miles for $4000 that I do not have.what are we overlooking? the car always run great until the leaking radiator problems. can someone help me get back on the road this would definitely put a smile on my late pops face since it was his car originally.

Has anyone checked for a head gasket leak? Have an overnight leakdown pressure test of the cooling system done. Or if your mechanic has a portable emissions analyzer, that’s a quick way to check the coolant for hydrocarbons that are a sign of a leaky head gasket:

Replaced radiator and water pump. Did anyone replace the much cheaper thermostat and radiator cap?

With the engine cold remove the radiator cap.

Start the engine and while the engine is idling watch the coolant in the radiator. If bubbles appear in the coolant while the engine idles the engine has a blown head gasket.


Are the fans running? One fan for engine cooling the other comes on when you turn on the AC. Air in the system can cause an overheat and no heat. The head gasket definitely could be bad, but these are a couple things to check to.