Engine/Transmission (1998.5 - 2002) Changing the thermostat

[brobeson]

My 2001 HO is starting to get hot while pulling hills under a load.



My 98 did this and for almost $300 the stealer relaced the thermostat and the proplem went away.



2 questions.



1) Where can you get a good price on a good thermostat, what temp should I get, 180 or 190 or?

2) Has anyone done this on a 2001 HO, is it EZ to do, any tips?



TIA



Bob

 

[LSMITH]

3 Bolts 10 minutes and you are gone. Get the thermostat from Cummins and change it. Cold engine you will lose less than a gallon of coolant.

 

[JR2]

I believe the part # for the 180 is 3954194. I was quoted $18 dollars at Cummis Northwest here in Anchorage AK. They did not have one so mine is on order.



Like Lsmith said... . less than 20 minutes and you are done.

 

[juicedcummins]

Get a 180 from cummins and they only take 10 mins to switch out.

There was a thead on fuel milage and t stats awhile back and some of the guys prefered the 180 over the 190. I have always been a believer that they should run 190+ but mine had and has a 180 and is very easy on fuel along with a few others.

My bet is that dc is using the same temp to activate the clutch fan on the 180 and 190. That would mean that the fan is running more and causing the milage diff if using the 190.

 

[mikeg135]

went to 180

I have the HO with the EZ and BDII's. I had the 190 and went to the 180 since I live in Georgia. I really did not have any problems running the 190 but it does much cooler with the 180. It is hard to say I am getting better fuel mileage.

 

[bdaniel]

I just replaced mine this weekend. $18 from a Cummins dealer and less than 10 minutes. Easiest thing I have done yet.



Does anyone know what Dodge wants for this thermostat? I've found a Cummins dealer now in the area so I WILL NOT be going to Dodge for Cummins parts. The price mark up is obscene.



Cummins dealer tossed out a figure of less than $2,000 for a new installed injection pump if I ever need one. Dodge wants close to $4,000 just for the pump.



Bobby

 

[brobeson]

Changing therm.

My local Stealer charged $275 to change the one on my '98.



Thats why I was looking at doing it myself.



Bob

 

[Hunter11]

I bought mine at Geno's and went from a 190* to a 180*. It has my truck running cooler and the needle stays steady on the guage where it was moving some with the 190*. With temps. here in the mid to high 90's mine seems to run better with the 180*. Took about 10mins. to change it out.

 

[sbiel]

thermostat source

Is the thermostat a cummins specific part or with a standard 180 degree unit work ???



Or is the cummins part a superior product to the aftermarket units ??



thanks, steve

 

[Tom G]

An EZ Job

On a scale of 1-10 (ten being hard) this must rate about a 1-2.

Did the following and took all of about 20 minutes.



1. Drained 3/4 gallon of antifreeze from radiator into container

2. Removed three bolts on thermostat using 5/16" socket

3, Removed old thermostat observing which end goes up

4. Inserted clean rag into thermostat opening

5. Cleaned 'O' ring and/or gasket area with putty knife

6. Tested new thermostat in kitched to ensure it worked

7. Removed now dirtry rag from thermostat opening

8. Installed new 180 degree thermostat in housing

9. Cleaned the treads on the thermostat bolts

10. Applied Anti-Seize to bolt threads

11. Applied Anti-Seize to mating surfaces of thermostat housing

12. Installed and tightened 3 bolts on housing

13. Re-installed about 80% of anti-freeze removed in radiator

14. Added the other 20% to coolant recovery tank

15. Test drove truck and checked for leaks



Sounds like a lot of steps but they go really fast. This is an easy task for those of you who want to learn a little more about your mighty Ram.



Tom Garven

Lake Havasu City, AZ

 

[fj40charles]

Has anyone proven that you get better mileage with the 180* thermostat? Also, I'm concerned about the way the fuel will burn.



I always thought you got a more complete combustion when the engine was warm. This is the logic used when people say it is better to tow with their vehicle because the engine gets hot and results in better combustion.



One more thing... How does a 180* thermostat work with the ECM? Does this affect the fueling?



I ended up ordering my Cummins thermstat from Cummins Mid South since the local Cummins dealer never seems to have the stuff I need in stock.



Charles

 

[Challenger-II]

Anyone know the Cummins part# for ther 190 degree? It will be for a '99 if that matters. Thanks

 

[1tuffram]

Originally posted by fj40charles

Has anyone proven that you get better mileage with the 180* thermostat? Also, I'm concerned about the way the fuel will burn.



I always thought you got a more complete combustion when the engine was warm. This is the logic used when people say it is better to tow with their vehicle because the engine gets hot and results in better combustion.



One more thing... How does a 180* thermostat work with the ECM? Does this affect the fueling?



I ended up ordering my Cummins thermstat from Cummins Mid South since the local Cummins dealer never seems to have the stuff I need in stock.



Charles

These are my same questions.

 

[Greg Boardman-RIP]

With the 190* tstat in running in 110* temps outside the fan was on most of the time. I don't know if the ecm cares about temp too much. I talked with a friend who is a 5star mechanic. He said that the thing needs to see 160* to run right. over that is personal preferance. I was seeing temps of 210* everyday in the summer heat. It is average of 106* every afternoon. I now can't hit 190*. I like that better. Even pulling hard on level 3x3 with a load of horses... ... Thats not too bad... ..... Greg

 

[brobeson]

Thanks for the help!

I hd a harder time getting the correct therm than I did changing it.



I ended up going to Dodge to get my new therm.



The stock one is a 190 for the 2001.



But it is a 180 for the 1999, emissions thing.



I bought the one for the 1999, a 180, put it in and everything is great.



The cost was $25. 00 from Dodge.



Bob