only time it overheats

[Markam Campbell]

is when i drive it. i can start it up and it will idle for at least half an hour, but as soon as I put it in gear, it starts to overheat severely. The top end has been gone through with a new radiator, three new thermostats, a new water pump, a new ECM, and a new cooling fan. The guy shot the parts cannon at it and missed. he also moved the sensor to the upper radiator hose, bad move. now he wants to give it to me. but he keeps forgetting. he has bought a new radiator hose and planes on moving the sensor back into the cylinder head.

 

[Markam Campbell]

he moved the sensor back to the cylinder head. he hasn't reprogramed the ecm. i guess that is up to me.

 

[PWilson_]

I'd first suspect an issue with the cooling system's flow under load. A collapsed lower radiator hose could be causing this. Under acceleration, the suction from the water pump can flatten a weak hose, restricting flow. Another thing to consider is a blockage in the engine's water passages, maybe from an old gasket or debris. Moving the sensor back to the cylinder head is a good move.. but if the ECM hasn't been reprogrammed to recognize the change, it might be using the wrong parameters for the fan. The fan coming on at the correct temperature is critical. It's a tough situation, but if the price is right and you're willing to do some diagnostics, it could be a good project!

 

[Markam Campbell]

So far the price is free if he ever turns loose of the vehicle. But he is busy with doctor appointments,and finding the paperwork, etc.

 

[Markam Campbell]

finally it is mine and it is home.

 

[Markam Campbell]

i was thinking something might be binding up in the trans or the transfer case.

 

[Markam Campbell]

Now everything works fine. it starts great, has lots of power, gets up to just under 210, and stays there. i don't know what changed, and it makes me nervous. now to fix the ac it blows outv warm air. probably low on freon.

 

[Markam Campbell]

going to check the freon this morning it is to hot to check it in the afternoon. what type of freon does it take.?

 

[Markam Campbell]

the freon pipes going to the rear were corroded through. i didn't have a way to fix them so i took it to a shop and had it done i might have been able to do it myself but it would have cost more in patients and tool than the shop charged. still overheats under load.