My 1996 dodge ram is overheating when the thermostat is in and when i take it out it doesnt overheat anymore. the radiator, water pump, hoses, and thermostat is new I've tried 3 different thermostats all with the same problem. I bought the truck with a blown radiator whitch blew the head gasket so i rebuilt the motor and now have this problem. the truck also will not idle and the timeing has been set and no check engine lights are on. any help would be greatly appreciated!!!

 

Are you installing the thermostat upside down??

Are you sure your in-dash gauge is accurate?

 

+1 on the gauge reading accurate. The gauge cluster in my '96 needs to be replaced....oddly enough the only gauges that work correctly are the temperature and oil pressure gauge. Have you checked the temp the PCM reports with a scan gauge or similar scanner?

 

Well, if you had no thermostat in there, and it DOESN't overheat. THat is actually a good thing. It means that your radiator is doing its job, and the clutch fan is doing its job.

However, it could be the water pump. It might not flow very well, and when you take out the thermostat, the flow is much less constricting. Thus more water can flow.

Everything you say leads to THERMOSTAT, but you said you tried 3 thermostats.....do you think you may have installed it upside down?

 

If the thermostat was installed three times wrong, that's a serious face palm moment.....

 

that is actually the dreaded double palm faceplam

 

i had the same problem, new everything, and it ended up being the sending unit was reading wrong

 

I've double checked and the thermostat is in rght both of the gauge sensors are new and the motors definatly hot at least with the thermostat. I talked to the guy that set the timing and he told me the water pump was good he just couldn't explain why the truck was overheating

 

Check and recheck the obvious.... I ended up having two problems with my '96 that caused an overheating problem. The issues were a leaking bypass hose and a freeze plug with a hole in it. Bars leak was used by the previous owner to band-aid the issue.

Don't recall but are you loosing coolant or have obvious drips somewhere?

 

A word about thermostats here. I had gone through three T-stats from Autozone. NOT ONE worked to OEM spec. I had installed three 192s and, one read super low, while, the other two read 240+ so, never assume that the parts you are getting work.

I later found out after bringing it back the 3rd time, that the ones they sell are not tested and are made in Mexico or Taiwan and use inferior materials / metals thus, they are way off.

I bought ONE at the dealer. It worked. I later bought after market 180 T-stats of high quality and those worked too without issue.

Now, I am not saying that the root problem is the t-stat is not working to spec but, merely conveying a lesson learned that I had gone through myself.

CM