I have a 1994 5.0 Bronco auto tranny that's running a little hot. On the word "NORMAL" in between the "L" and "H" on the temp gauge, it reads constant on the "A". It fluctuates a little from the end of the "M" to the end of the "A". I've replaced the thermostat (195 degrees I think) ECT sensor and ECT sender and the radiator cap. I've flushed out the coolant... The coolant in the radiator looks low after I let it sit for a day or two... But there's plenty of coolant in the overflow tank. The fan seems nice and solid and doesn't have any play in it. No noise or leaking from the water pump... Maybe the radiator needs replaced? Any opinions would be helpful, parts can get a little expensive in this area to be replacing random things..

 

One of the best things I have done is good manual temp and oil pressure gauges. Put a little clamp or cable tie on the reservoir hose at the radiator cap and check for leaks. It may be sucking air when cooling down overnight. Replacing my oxygen sensor made a big difference in eliminating the lean issue.

 

Ditto to everything b4hntn said. I only would add that the ECT sensor is NOT the trigger for the temp gauge. It has its own sending unit separate from the ECT. Make sure the fan clutch is doing its job well. You should only get about one revolution out of the fan when spinning it by hand with a cold engine. (engine OFF please... I know, I know but you never know who will read these things).

 

check your plugs also. if you have a blown gasket it may not be showing on the exterior of the motor. if the motor is running lean the plugs should show this also. have you replaced the temp gauge sender also? which direction did you install the tstat, perhaps you put it in backwards.

 

To b4hntn: I'll have to try your idea. And I have a newer O2 sensor, but no cats.



To Greystreak92: I did replace the ECT sender unit. I get about a quarter of a revolution on the fan though. Is that normal? Also... the temp gauge seems to be the lowest when not on the gas.



To Kemicalburns: My plugs are all good. And I did a block fluid test to check for a bad head gasket, it was fine. I did replaces the ECT sender unit, and the thermostat was installed correctly.


THANK YOU ALL FOR REPLYING

 

are you running a fan shroud? if not that alone could be part of the issue

 

Yes there's a fan shroud.

 

Hey Kemicalburns, where'd you get that front brush guard?

 

i had it built by guy in my 4wd club.

 

New fan clutch fixed my 94 5.8

 

Was yours doing the same thing?

 

mine was doing it in stop & go traffic, on the highway it was fine, but it was also summer in Houston

 

Mines doing in now, in freezing weather in PA. I just had it running, the heat doesn't get real hot, it's more like a warm. The fan doesn't kick in, I think it may speed up with higher RPM's but from what I've read the fan clutch should kick in (quite obviously) at a higher temperature. And cold or warm, I only get 1/4 of a revolution on the fan.

 

did it do it in summer or did it just start? i never had in problem in winter but temps in the 30's is cold around here, like B4 said it could be a gauge issue, as far as coolant level mine is always right at the bottom of the neck when i open the cap. one thing i have noticed on both my broncs is i lose coolant from the reservoir. dont know where it goes. pressured tested them & no loss of pressure but they always get low.

 

I haven't had the Bronco long, the temp gauge was reading cold when I got it, the guy said it was just a low temp thermostat. Eventually it started jumping from all the way cold to the middle and back down which is why I changed the ECT sender, sensor, and thermostat (back to a 195 degree) After those changes the gauge acts fine, heats up normal just gets too hot. And Before these changes I seemed to have been losing antifreeze from the resevoir but not any more. Maybe it is a gauge issue? How can I manually check the coolant temp? Maybe it would be ok if I stuck a 185 thermostat back in? But then maybe I'd have no heat? Maybe I should try some of that Water Wetter? Idk really... just guesses... I've just noticed some splash marks inside the fan shroud, it's tinted green (antifreeze of course) There was a very small wet area but it didn't have any smell to it. There was also a small wet area underneath the drain plug, but as much as I've watched I never actually saw anything leak.