My 96 4.0 overheats a lot. I have installed a new 3 row radiator (last year), fan clutch was new when the radiator went in. The water pump was new when I purchased it back in 2009 and I have only put 15K miles on it since. There is also no obstructions in front of the radiator grill. The previous owner put in head gasket sealer and that stuff pretty much caused a lot of gunk inside. I cleaned most of it out. I have since tried to flush the system every year and the last 2 years I have used Irontite Thoroflush. It seems like it works, but why whenever I am in traffic and not moving speedily, my dummy light comes on stating I am overheating? I did purchase a new thermostat yesterday. Is there anything else I should do. Please note that I have done my research on youtube, watching the videos of how to flush this system. I have even spoke to 2 mechanics who are friends and they said I have done everything they would have done.

 

Did you ever wonder why the previous owner used head gasket sealer? Are you overheating because of a blown head gasket? Have you checked?

Also, you mention a thermostat. Is the current thermostat defective? Does your thermostat not open? Have you tested it in a pot of boiling water?

I'm more inclined to think the thermostat isn't opening because of how fast you overheat, but either scenario is possible.

 

​​​​​​I agree with the above but would add that if you are relying on the idiot light to tell you it's overheating it might be an idea to use an ir thermometer to confirm that it actually is. Bad sensors and all

 

I agree with the two posts above.

The mechanics you talked to should have told you to confirm overheating with an infrared thermometer, pressure test the coolant system, check for coolant loss, and check for coolant in oil.

 

Bad fan clutch? You still have the fan shroud installed?

 

Get a "block tester"/combustion gas tester from a parts place that rents tools, buy the test fluid and check at the radiator cap for combustion gas. A positive there indicates a bad head gasket, cracked head or other inconvenient problem.

 

Yes my fan shroud is still on there.

 

My mechanic friend seemed to think that my thermostat was bad. I went to Autozone and they tried to sell me one with a new housing (dont need that). They they said they had a t-stat but it was 160 degree. I said no I need a 195. I got home to find my 10 year old lab not doing so well. His gums, ear flaps and wicks were all white. I took him to the hospital and they did an ultrasound and took a sample of his belly. Turns out he was bleeding internally probably caused by cancer. I called my family to say goodbye. It was all of a sudden within 1 day of him playing and having fun. Sorry for the story. I just remembered that when I left Autozone I went home and this is when my Sunday evening and days that followed haven't been so good.

 

Sorry to hear about all these issues coming at once. Hang in there.

 

It is a possibility that your aux elec fan is not coming on..

 

Everything is working properly. I just bought a 195 degree t-stat and will install it soon.