Engine/Transmission (1998.5 - 2002) T-stat Reliability Problem

[Rambling]

I noticed my temp was only coming up to about 165°. Strongly suspect my t-stat again. This will be the fourth T-stat I've had to replace in 5 yrs with less than 50k miles on the truck. I replaced it last March with a "genu-whine" MOPAR part. Truck gets driven weekly just to keep the fluids through the engine.



T-stat failure, so far, has been the same. The "U" shaped frame breaks at the point where it mates to the base. Various dealers/places have done the work.



Any clues?

 

[CEpp]

165? its cold outside and the truck will run cold. just a thought. does it break when installled? does it bypass coolant when it breaks?

 

[Rambling]

Oops!

Thanks for the thought CEpp. I forgot to mention the wheels and I are in Fl.



As to when it breaks, it breaks while in service. T-stat appears to work normal (normal temp 180°) until it breaks. Then the engine temp never comes up to temp.

 

[rblomquist]

Think I have the same problem. I've been suspect of the fan being stuck on but I've never heard the big noise that everyone says is associated with it kicking on. My T-stat is only about a year and a half old but sounds like they can go bad quickly.



The one that's in there came direct from Cummins.

 

[Rambling]

Rblomquist, if your temp isn't coming up to normal it is more likely the T-stat than the fan always on. I put this one in about 9 months ago when I had the anti-freeze changed(same symptom then). I haven't heard the fan even when I've towed the 5'er.



As I said, this will be my fourth unit and the failure symptom has always been the same, water won't come up to the proper temperature.



I hope you have better luck at getting a good thermostat than I have.

 

[rblomquist]

I've not been too overly worried about it as the truck is pretty much only used for towing the TT now and it will run up to 170-190 while the TT is in tow but it is aggravating given how much they want for a thermostat.



I've never heard the fan kick on with either t-stat that I've had in the truck and that includes plenty of hard towing in well over 100 degree heat.

 

[OTRPU]

Maybe I've gotta problem and don't know it. About the only time my water temp gets to the middle of the stock temp guage is when haulin a trailer. Thing runs pretty regular at half way tween the left end and center marks. New engine, came with a new thermostat so I assumed everything was working properly. If I really get on it haulin uphill the needle will go about a needle width past the center mark. Been this way for a couple months. Then this trip running I-80W through Nebraska all at once the temp seems to be hovering just to the left of the center mark. Engine has alittle over 30k on it. I got a new OEM radiator when I had the engine installed and a new fan clutch also. Did this cause last engine was heating too easy and boiling. Don't knows I've ever heard the fan kick on in the Ram. My 96 PSD there was no doubt when the fan kicked on, it was loud. Don't know if I'm working right or not. Been running lots of cold weather lately, engines always on the cool side. But I have cabin heat through the heater.



Cheers,

Steve J

 

[Supermod56]

I would check the gauge, the laser temp guns are worthless on cooling systems, I found that out on the race car. Get a temp probe and stick it in the radiator when the thing is "hot", you could use a digital thermometer, that's what I switched to. (After buying 3 gauges)

Tom