Engine/Transmission (1998.5 - 2002) 180 vs 190 thermostat questions?

[fj40charles]

I'm still trying to figure out which thermostat is better to use.



I talked to Cummins today and did some searches and have come to the following conclusions:



1. 99 Dodge trucks came from the factory with 180* thermostats.

2. 2000 and up trucks came from the factory with 190* for emission reasons.

3. Cummins recommends 180* thermostat for their motors used in non Dodge applications.

4. Our ECM need to see 165* in order to consider the engine to be fully warmed up.

5. Cummins will not "recommend" a 180* thermostat because it would affect emissions and they don't want to get in trouble with the EPA.

6. Timing advance only happens when the temperature is like 40* or below.



Can someone with more knowledge confirm or dispute the comments above.



I installed a 180* thermostat in my 2000 truck and it seems to have more power, but does not seem to be as smooth running.



Also, any chance I'll be getting more cylinder washdown with a 180* thermostat? Will the Dodge ECM actually notice a 10 degree temperature difference?



Thanks in advance,

Charles

 

[Cowboy Medic]

Was in to the dealer this morning for replacement of the lift pump and spent a few minutes talking to the tech and then went to parts to get a new thermostat priced to compare to other places. Both the tech and my brother who works on OTR rigs said they could only see one difference the 180 would make and that would be to keep temp farther below where the fan engages and so therefore the motor doesn't work as Hard. Mine is a 99 so I have the 180. my brothers is a 2001 and he switched just because the fan was always running in the summertime.

 

[Wolfgang]

I just changed mine out before taking my trailer out over the 4th. the only difference I noticed was that the truck did run cooler. The cooling fan came on a lot less often

 

[fj40charles]

TTT

 

[Rob Thomas]

Well, since DC wanted the 190* in for emission purposes, that was good enough for me to yank it out, and install the 180*, and thats where the needle sits, 180*. No prblems or complaints yet.



Later, Rob

 

[roadranger]

I changed to a 180 because the POS factory 190 wouldn't open up all the way... .



Running 75mph with a camper on back and towing a trailer would put temp at 210-215 and the fan on all the time.



Put the 180 in, and run like above with the A/C on too, and it STILL reads 180, with NO fan running.

 

[Tomeygun]

do you have a part #?



thanks



(no wonder my 99 would never hit 190, but my 2002 does so very quickly and up to 210. hmmm)

 

[fj40charles]

Cummins part # 3954194 for the 180 degree thermostat. This part number is good for all 24V engines. This comes with the gasket and cost is around 16. 00 or so. .

 

[TomGolden]

Would anyone happen to have a Napa or other non-Cummins part # for the 180* T-stat for a 2001 24 valver? It's a bit of a trip to Cummins West for me, and I have a Napa less than a mile from my house



Thanks,

Tom

 

[mobilescout]

I went to the Stealer to purchase a 190* thermostat to replace my bad one and ask the parts guy to show me a 180*. Upon comparison, they were not the same. The gasket was located on the outer rim of the 190* unlike the 180*. Has anyone else noticed this? I have a 2002 HO. I would like to try a 180* if I could get the part # either for Dodge or Cummins.

 

[STRALEY]

I also have an '02 and would like to make sure the Cummins 3954194 part number will work. I am sure it will but just want to double check.



Jeremy

 

[Royal]

Charles--Thanks for the info that 99's have a 180 T stat. Thats exactly where mine runs. I always thought I had a 190,and my gauge was 10 off. I have never seen above 190 and I pull a 24 ft 5er in this AZ desert,and I have never heard the fan engage. I am still stock power wise. I travel to Colorado every summer ,thru the hills in NM. & over Raton pass and never heat up. I have a screen in front of my condenser/radiator since new--No bugs or dirt.

 

[fj40charles]

You're welcome Royal! Just trying to share some info...

One thing I have noticed and experienced myself... There is a high frequency of thermostat housings cracking on the bottom side. This certainly explained why my truck too forever to heat up.



Charles

 

[WadePatton]

I just dropped a 180 in. Truck be cooler, less fan. Feel better about leaving it running--keeping the dog cool.



And what a beautifully easy and simple set-up, the housing and gasket and all.