Shrimper

Dose anyone know what the part # is for a 180deg thermostat for my 2003 3500 truck? I called another dealer about the 210-220 heat when pulling and he asked me if I had a ranch hand front bumper. I told him yes and he said that some of these bumpers are slowing the air flow down and causing them to run hotter. That seemed reasonable, so I went home and took the ranch hand bumper off to check it. 15 minuites later the temp went down 1-2 degrees, but I really couldn't tell because the outside temp droped from 92 to 90 at 6:00PM. I live in South Texas and with a cold winter here we might see temps to 32 deg for 1-2 days sometimes lower. I think with the heat that we see around here isn't going to hurt the truck putting a 180 deg thermostat in it. Any opinions would help also. Thanks, Shrimper

Dodgezilla

Do a search here. I posted the part number a while back but I don't remember what it was. I run a 180 stat and have had no problems whatsoever, even in the winter...... Many others here will disagree but my experience has been good...

Hunter11

I will be watching this with interest. I have been wondering the effect it might have changing my 05 over to a 180* thermostat. I ran one in my 01 for 4 years with no problems at all. It has been 95* and higher here for over 2 weeks now and rarely gets below freezing in the winter. Does anyone know what the stock stat is in the 05's? Wonder if you can get a 190* for the 3rd gen trucks.

Shrimper

The 2003 has the 190 in it and the 2005 has the same I believe. I am looking to put the 180 so the trans temp comes down with the engine temp. Shrimper

Hunter11

Shrimper, my 01 came with a 190* in it so maybe that is what they use across the board. I would really like for mine to run a little cooler. If someone has a part number for the 180* thermostat that will fit the 03 thru 05 could they post it? Also does anyone know of a on-line source for the 180* stat? Thanks

Shrimper

I pulled the 1998 1/2 24 valve thermostat and compared it to the 190 for the 2003. The 2003 had a rubber gasket around it and was smaller in diameter than the 1998. So I was thinking that the 2003 HO might have something to do with it. We need someone that has change one in a 2003 or later HO so we will know what to get. The Cummins dealer had the 3967195 180 deg in stock but I was afraid that it would not be the correct one. The other thing is they didn't have a gasket to go with it. Thanks Again, Shrimper

Dodgezilla

Shrimper, I reused the one from my 98 24 valve. It has worked without problem ever since I bought my 03 new.....

mikmaze

Hmmmmmm makin me think now, I had a cooler themostat in my gasser for years, cooler, kept oil a bit thicker, fooled engine comp to give more fuel.... I thought diesels wanted to be hot to make power???? what would the ideal thermometer be as far as power, I'm not worried about winter heat, I can get enough, heck the thermostat in my old gasser was a 165 deg and I had no problems stayin warm enough... this sounds like a nice inexpensive way to make it easier on my engine, a cool cummins gotta be a happy cummins.

Dodgezilla

I can tell you that when my truck was on the dyno we had to let it warm up for quite a while in order to get the most power out of it. You may get more total Hp/Tq with a warmer engine, but in a real world application I would rather have the cooler running engine. It just makes me feel better.....

mikmaze

I'm with ya on that zilla, I want whats best for my engine in the longrun, your peak power couldn't have been that dramatically different.

Hunter11

So does anyone know of a on-line source for a 180* that will work on a 05?

tempforce

i found in my '83' f@#d that with a 195'F thermostat, my truck runs better and smokes less.
i would put in a hotter one if i could find one.
on some older (90's) models a 205'F thermo was available.
ford is using a cooler thermo to reduce nox emissions.
could be the same for the cummins.

nickleinonen

hmm... maybe it's just me, but i want my engine to run a bit hotter... a 195° or 200° is what i want...

sr mk11mod0

I believe this is the 180 t-stat cummins #3954194. I tried it for about 3 weeks and didn't like it. I too wanted my engine to run a little cooler, but it actualy ran hotter. When engine was just starting to warm up it would stay at approx. 180 degree on guage which was what I expected. Once it ran for about an hour pulling or not(at 70mph) in 90+ degree day it would run up to 1/8" past the 200 on guage and would stay there. It was strange I know. Thought maybe it was a bad one but just put my stock one back in. If you get one, check out the bottom of the stat and you will notice they are not close to being to same where the bottom covers up the recirculatin hole in head. Stock seems to fit in the hole and the other has a spring loaded cap type.

Maybe ya'll will have better luck.

Chubby

Going to a lower temp thermostat will not make the motor run any cooler In very hot temps, the 195 degree is already wide open at 195-200 degrees. The only way a cooler stat will help if in some way it flows more coolent. Running cooler will take more air flow over the rad core or a bigger radiator.