180 Degree Thermostat and Fluid Change

[Big-D]

Changed the thermostat and coolant in my ’99 yesterday and could only remove slightly over 4 ½ gallons. That was after removing the heater hose and using compressed air (2 pounds) to drain the heater core and engine. Probably should have asked the “pros” here for a little advice, but thought the compressed air would push the antifreeze out to atleast remove 5 plus gallons. Didn’t happen.



The Cummins tech in Seattle stated I didn’t need to go to that much trouble, but I wanted to get as much old “green” antifreeze out before replacing with the blue 50/50 mix by Cummins. The job didn’t take long, but when I do it again I will fill the engine with fluid to the bottom of the thermostat housing before bolting things together. I takes too long for the air to bleed out through the thermostat bleed holes otherwise.



Dave

 

[Evan A. Beck]

WHat I dod when I change coolant in any truck, is jack up the back end as high as you can. This will allow you to get as much coolant out of it as you can. Just be sure to put the back end back on the ground before filling.

 

[Mad Max]

1. Why the Tiddy Bowl coolant, it has DCA in it, your ISB doesn't need DCA becuase it doesn't have pressed in cylinder liners. (wet liners).



2. Why not flush w/ water until clear then drain, add new coolant, drain, repeat until what comes out looks like new coolant and finish filling it.



Sure seems like you're putting yourself through a lot of needless heartache for a half gallon of coolant.



MaX

 

[DAT]

What is the recommended coolant for the 24V ISB?

 

[mikeg135]

I just changed mine tonight. I went to the 180* thermo from Cummins. BTW, the man at cummins could not believe that dodge put a 190 in the truck. He was saying something about it is a totally electronic motor and sensors feed informtaion to the computer and 10 degrees is a pretty drastic difference. He went on to say that if a dodge came into his shop with a 190 thermo. that they would not warranty the work if it is temperature related failure.



He just continued to shake his head the entire time I was there.



The truck is running noticably cooler. Does not even come close to the 190* mark on the temp guage.



I used the Prestone 5/150. It states that it is silicate and phosphate free. So I think I will be OK.



I was only able to add 4 gallons. It was dark when I got back from the test drive so I will how much more I need to add in the morning.



Mike

 

[ralphr]

coolant??

thought I read texaco coolant?? or was that texaco transmission fluid??? does anybody have info on the correct type to use???

 

[Animal]

Originally posted by mikeg135

I just changed mine tonight. I went to the 180* thermo from Cummins. BTW, the man at cummins could not believe that dodge put a 190 in the truck. He was saying something about it is a totally electronic motor and sensors feed informtaion to the computer and 10 degrees is a pretty drastic difference. He went on to say that if a dodge came into his shop with a 190 thermo. that they would not warranty the work if it is temperature related failure.



Mike

This makes no sense, first off Dodge, not Cummins, warranties the engine in the Ram. As to the 190 thermo, dodge programs the engine ECM for the 190-thermo temp, changing to a 180 will throw off the ECM program and maybe the Dodge warranty of the engine!

 

[1tuffram]

Originally posted by Animal





This makes no sense, first off Dodge, not Cummins, warranties the engine in the Ram. As to the 190 thermo, dodge programs the engine ECM for the 190-thermo temp, changing to a 180 will throw off the ECM program and maybe the Dodge warranty of the engine!

I was kind of thinking the same thing that DC has maybe changed some of the ECM parameters to compensate for the 190* t-stat. But then again people are swapping to a 180* t-stat and seeing improved fuel mileage, soooooo who knows

 

[Animal]

1tuffram,



I had a 99 diesel and it came stock with a 180 deg thermo, I changed to out for a 195 deg. Up here in Alaska we need all the heat we can get. I'm not sure what temp thermostat is used on the 2000 up.



Also diesel engines are heat engines, they are more efficient the warmer they run. I'm looking into running NPG+ in mine and using a 210 deg thermostat.

 

[Mad Max]

I replaced the OEM thermostat in my 2001. 5 ETH/DEE because the gauge seldom read 190 degrees.



I removed a cummins 190' thermostat and replaced it with one bearing the exact same part number AND EVEN THE NEW ONE EXHIBITS the same behavior.



Coolant?



transmission for DEE's (6speeds) calls for TEXACO MTX.



Been warnings about Havoline Long Life Coolant in the passed concerning seal compatability. Our 24V's don't require DCA so an approve green coolant mix at the dilution in our Owners manual should be a safe bet.



Some have gone with the low tox type polypropelene (sp) type coolants, but do some research before you spend your hard earned dollars as it is more expen$ive.



I buy peak pre-mix, change every two years and add TWO bottles of regular redline water wetter post 2yr flushing.



If in doubt, a hydrometer is/would be a good investment.



MaX

 

[1tuffram]

Originally posted by Animal

1tuffram,



I had a 99 diesel and it came stock with a 180 deg thermo, I changed to out for a 195 deg. Up here in Alaska we need all the heat we can get. I'm not sure what temp thermostat is used on the 2000 up.



Also diesel engines are heat engines, they are more efficient the warmer they run. I'm looking into running NPG+ in mine and using a 210 deg thermostat.

I also thought diesels where more effiecient at higher operating temps (to a point anyway), which is part of the reason fuel economy is better in summer (not using winter blended fuel also being a reason).



I noticed on my new baby I just brought home tonight (2002 ETH/DEE) the temp gauge stays rock solid at 190* or maybe just a hair above.

 

[mikeg135]

I think I will trust the Cummins Dealer over the dodge dealer when it comes to recommendations. After all they were the ones that built the motor. Although Dodge may have reprogrammed the ECM to handle the 190* themostat, that is not the temp according to Cummins that the truck should run at.



My question is if the 190 is correct why are members reporting better fuel economy with the 180. That sounds to me like the motor is running more efficiently.



Maybe in colder climates the higher thermo is better. But the hot stagnant summers we have here in GA, I think the 180 is the way to go.



Mike

 

[PRout]

Originally posted by mikeg135





My question is if the 190 is correct why are members reporting better fuel economy with the 180. That sounds to me like the motor is running more efficiently.



Mike

Actually, others may have reported that, but mine does not get better mileage w/ the cooler therm.



If anything, mileage has gone down slightly & the truck may not be running quite as smooth as it did before. There was a noticable smoothness the truck used to have when it came up to full temp (w/ the 190) that it doesnt seem to have w/ the 180. This is only sop opinion, and also spring/summer air temps may have lowered the Mpg so its hard to say for sure.



I do like the idea of the motor running cooler just because heat is a major cause of wear. Motors usually last longer when they ran cooler. The other factor here is cylinder temps are still high no matter what the therm is, so it seems that the fuel should burn fine either way if your cruise egt is 600 or so. I wouldnt think the thermostat would affect that much.

 

[roadranger]

Thermostats

Last summer my '01 HO would run HOT towing/hauling at 70+ mph highway speeds. To the point that the fan would come on- THAT doesn't help fuel mileage.



Changed out the OEM 190* thermo for a Geno's 180* and now it doesn't get past the 190* mark on the gauge, and NO fan noise.

 

[Benson]

I went to buy a stat from Cummins West and the guy wanted to know my engine serial number. I didn't have it and didn't have the truck with me so I took a chance and bought the stat they had. Got it home and called him with my serial number and he told me that was not the correct thermostat. It was a 180. He then oredered the correct stat and I picked it up today. It is a 190, part number 3937171. This is for a late '01 24 valver. I don't know if there is any other difference in the thermostat other than the temp setting. I wanted to try the 180 but don't know if I'll mess with it now. It wouldn't surprise me if the 190 was implemented for reduced emissions for the later model.

 

[Opz01]

I was told by Cummins that my 2001 don't use 190 thermostats and they needed my engine s/n before they would sell me a thermostat. They had to order my thermostat p/n 3937171 ($20. 67) when the thermostat came in it was a 190. (Which I am going to keep for winter. ) I wanted to try the 180, so I phoned the next day with just the p/n for a 180 and had it waiting in will call. P/N 3954194 ($16. 64) which was in stock by the way. Being hard headed paid off for me as I am getting better gas milage 1. 4 mpg according to the computer. And it does seem torquier. Not to mention it does get to it's operating temp quicker.

 

[Big_Daddy_T]

Has anyone had a thermostat fail? Mine went out and they absolutely wouldnt believe me. Accused me of being stupid.