over heating 4.0

[katt68]

my 92 4.0 is over heating sometimes. yes only sometimes. it is very wierd. i noticed too just this evening, that while running with the cap off of the rad instead of the fluid dropping as you would expect when the thermostat opens, instead it was boiling up and over. my thermostat was just recently changed. please help me.

 

[Alec]

It is possible your replacement tstat is bad. I'd replace both the tstat and radiator cap.

 

[MyExpWork]

Sounds like a bad T-stat. I changed mine cuz it was stuck open with a new one that would stick untill it got really hot, then really cold.

From what I have read on this board, T-stats are a common issue.

Brian

 

[tenikiwon]

It's common to have a new T-stat go bad, just swap it out again with another one.