2003 4.6L Overheating problem

[larry75]

my 2003 Ford Explorer 4.6L 4x4 is overheating. Originally the intake manifold had cracked allowing water to run into number 1 cylinder. I replaced the manifold with the new design, at the same time replace the water pump, thermostat, hoses, Clutch Fan and purged the system and ran a CO test at the overflow box to check for a blown head gasket. The engine runs fine in the city. Up on the interstate after about ten min at highway speeds the engine goes to overheat and blows antifreeze our of the overflow container. I don't know what to check next?. Any help would be appreciated.

 

[rocco123]

Thermostat in backwards? Fan clutch?

 

[Joe in NY]

I would check your pressure cap. Fords are known for bad pressure caps.

 

[larry75]

Thermostat is installed correctly. The Fan Clutch is brand new. Has anyone heard of transmission problems causing overheating?

 

[decipha]

sounds like the head gasket is seeping

 

[imp]

Check for combustion gases in the coolant, in the radiator. Kits are available to "sniff" their presence. Assume the heads were not removed? Head gaskets have been known and seen, to leak combustion gases into the water jacket only under relatively high load, maintaining sealed condition oherwie.

Just a thought., imp

 

[Number Twelve]

Has anyone heard of transmission problems causing overheating?

I don't think so. If the tranny is working right, 99% of the power goes out its tail (shaft). If it isn't, it burns the bejesus out of a clutch pack, and you're going to figure out the transmission is bad, real quick. It takes less than a minute of slipping to get a clutch plate so hot that it turns blue. The innards just aren't built to absorb a dozen horsepower for more than a few seconds. I can imagine if the torque converter doesn't lock up, that energy will be converted into tranny fluid heat and go to the radiator, but these are cold blooded beasts. (I had a bad radiator cap and only lost a quart in 6 months.) Besides, several million cars didn't overheat before lock-up torque converters were invented. So, just from a physics point of view, and the dozen transmissions I rebuilt, I don't think so.

Now, watch the real tranny guy come in here and catch me being ignorant.

 

[Joe in NY]

Step 1) Is the Top hose getting hot?
Step 2) Is the bottom hose Cold, Warm, or Hot?
Step 3) Does the system pressurize when Hot? Is it hard to squeeze the hoses?

Answer those three questions and that will be a great start. (Let it run a while and check)

 

[lincolnshibuya]

sounds like there's still air in the system. how did you bleed it?