Cracked Heads/ overheating

[lunafishon]

Hi, I just bought a new explorer because I drowned my old one, and the guy who sold it to me pulled the thermostat to cover up the overheating problems. I tore it apart and both heads were cracked. Got new heads and head bolts ect. and rebuilt the top end proper. The head gasket is holding, no leaks, cool. Test drive didn't go so well, first mountain started heating up. If the heaters not on the damn thing heats up even on flat ground. I'm thinking radiator, clutch fan, or pressure cap, but seems to hold pressure. I'm not rich and need a truck and can't spend to much more to get this thing running good. But I do have a radiator laying around from an auto 95. I think it'll fit on my 92 5 speed. THANKS

 

[Anime]

Pulling a thermostat won't cover up any overheating problems, as the cooling system on these is pressure dependent and requires the thermostat to cool properly.

The temperature gauge needle should be in the middle at normal operating temperature. If the needle tends to climb and stay much higher than that, with A/C off and without any load, then either the thermostat isn't opening at the correct 190-195 degree temp, or theres some issue with the water pump/hoses/radiator/fan clutch that isn't working to transfer heat the way it should. The easiest thing to check would be the cap, maybe make sure theres a full radiator of coolant, then double check the fan clutch for proper operation.

Going to a double core radiator is an option, but getting the right combo of manual/auto tranny stuff together on the cooling system for proper operation can be a challenge.

 

[surf]

I think Anime has it pegged. If you are not losing coolant then the likely cause is bad cap, water pump or fan clutch. Cheap options are to replace or test the cap, use a pressure washer to clean the fins on the radiator and flush the system and put in fresh coolant. If that does not fix you may have to look at replacing the water pump and/or fan clutch.

 

[lunafishon]

Thanks, is there a good way to test the fan clutch?

 

[surf]

When the engine is warmed up you can shut it off and then see if you can turn the fan by hand. It should be difficult to turn. If it spins easily it means the clutch is not engaging.

 

[lunafishon]

Thanks, the clutch is really easy to turn with warm. I replace that next then see were I'm at. I just really don't want to get it hot and ruin the work I already did.