Overheating Update ... pulling my hair out!

[Richard Lange 2]

This is a follow up to 2 earlier posts about my truck sending boiling liquid in to the resevoir after I turn it off. The good news is the boiling over has stopped. Bad news is it still starts to over heat after 20+ miles of drving with the AC on during the day. At night & in the morning I can drive over 100 miles with the AC on and it is fine, or in the afternoon I can drive without the AC on and it runs fine. But with the AC on driving home from work around 5 pm it statrs to get above the middle part of the gauge on the dashboard and starts to shift funny, and not brake very well. If I turn off the AC everything reverts to normal.



I have now flushed the system, changed the radiator cap, changed the thermostat, checked the hoses, and replaced the sensor behind the thermostat. The water pump was changed more than a year, but less than 2 years ago (no leaks from it).



Someone mentioned the fan clutch going out. How hard is this to change on my own and what will the part run me? I followed the link below and according to it my fine clutch is still OK.



http://aarc.epnet.com/application/9110/9110CH03_CLUTCH_FAN_DIAGNOSIS.htm



Could it have anything to do with my AC unit? Hot and cold air work fine, but during the winter my heater occasionally hums for few minutes. Nothing major just an unusual sound.



I really do not want to take it to Ford becuase I am out of warranty and low on funds, but I am about ready to give up.



Please let me know if onyone has anymore ideas.

Thanks!

 

[Kevin Palmer]

Try this.

Run it up to temp doing normal driving. REMOVE the keys so no one cuts your arm off. Open the hood. Put the palm of your hand on the face (the coolong fins) of the radiator. Move your hand all over the face. It should be hottest near the top and transfer to warm at the bottom. If you feel a COLD spot then the radiator os plugged. If so, flushing it will NOT do what you need to do. You will need to replace the radiator or have it rodded. Rodded is when the tank is removed and they shove rods thru the core to unplug the radiator.

 

[Ed C]

Here's some other stuff to you could check in accordance with the repair manual.



Improper grade of oil

radiator core blocked or radiator grille dirty and restricted

cooling system being pressurized by engine compression, could be due to cracked head or block or leaking head gasket.

Loose waterpump drive belt



I don't think it has anything to do with A/C system.



Good luck

Ed

 

[Todd Z]

Sounds like it is time for a compression check, I think the head gasket is blown...

Todd Z

 

[Tim Turner]

I've had this exact same thing happen to me the past two days. The truck will start out fine, but after about 5 miles of driving, the thermostat gauge starts to rise above the normal point of half way. That's when braking becomes mushy and harsh shifting into second occurs. Going up a slight incline becomes a chore. I have to mash the petal into the floor in order for it to shift. The temperature gauge soars to the highest point at times and the check gage light comes on. Selecting the vent or A/C cycle only seems to make the problem worse. Sorry I can't be of any help, just letting you know you're not the only one.