Engine/Transmission (1998.5 - 2002) thermostat question

[cmills]

Hello everybody this is Cory again I also have the fan clutch topic, well today when I went out to drive the truck it would only warm up to about 165 degrees, then when I put a trailer behind it with a mower on it (5000lbs trailer and mower) I could just barley after running it hard for a while get it up to where it normally runs when empty, around 185 or so. Would you say that it is just the thermostat sticking open or something else. The truck has 155,000 miles on it and it is the original thermostat, and it has a ESN # later than the one in the TSB for having a bad thermostat.



If I do need a new thermostat can I get it a NAPA or AUTO ZONE or do I have to go to Cummins or Dodge? And I would assume that none of them would end up giving me the old (bad) thermostat, right.



Any info would be great, and any part numbers would help also.



Thanks,



Cory

 

[LSMITH]

Sounds like the thermostat is stuck open to me too. I would buy it where ever I could, but I would start looking at Cummins, then go to Napa, then to the discount stores. I doubt more than one company makes the thermostats for the ISB, but I could be wrong.



I bought one at Cummins, was around $15-20. Try a search for the part number.

 

[cmills]

part number

Thanks, I tried looking for a part number and I got a few different ones and I think they were for 2000 and 2001's, does that matter? The part number I saw the most was 3954194 will that work on my 99?



Thanks again

Cory

 

[LSMITH]

Yeah cory, but it is a 180* and not the 190* that our trucks came with. I was not able to find the 190* when I did mine, the 180 * is working fine.

 

[cmills]

Thanks LSMITH, I assume 3954194 is a cummins part number right? If it works good for you it should work good for me, I don't see where 10* will make any difference. By the way does your fan clutch ever engage?



Thanks Cory

 

[LSMITH]

My fan clutch does engage but only on hot days when I drive it like I borrowed it from a brother-in-law and the AC is on



The 395 number sounds like a Cummins # for sure.

 

[cmills]

Thanks again,I'm going to try and get the thermostat tomorrow at a local heavy duty truck service center and I'm sure they will have to get it from somewhere else (like usual) unless that same thermostat is used in something else also.



Cory