No offense Chubby, but my truck runs at about 180 degrees most days where before it would get up to around the 200 degree mark. Now, on super hot days especially while towing, it will run hotter but 90 percent of the time I run around at 180 degrees. When I say it will run hotter I'm talking about 200 to 210 degrees. That's where it used to run stock and it would go up from there on a hot day! I've heard the arguments for years that lower stats don't help and for years I have gotten the benefits.. To each his own.........

In the end though, if you want to run cooler, turn the A/C on. It makes the fan kick on and that fan works awesome......

 

I think the dodge ram has an oversized(for lack of a better word) cooling system and a cooler stat should under hi-way conditions make the engine run cooler. The 180 stat does in fact have a bigger hole so it should flow more coolant. Why mine ran hotter has me stumped. It may have been defective.

Dodgezilla, was that the same part# t-state as you are using?

Thanks

 

The part number on the one I am currently running is Cummins # 3954194. As I said previously I ran this on my 98 24 valve and pulled it out before trading it in and now I have it in my 03. Works fine....

 

how hard is this to change, and is there any real benefit?

 

I was thinking about going to the 180 stat. I noticed when I was towing this weekend in hot weather. When the engine water temp got over 190, my tranny temp started to climb also.

 

the 3967195 is a good thermostat and will cool the engine good while towing. Look close at some of them and you will see 180-190 stamped on them. The only difference I see in any of them is the max temperature not the cruising temperature. They tried to comprimise between fast warmup time and max heat.

 

The thermostat in our 2003s are 3954830 thats 190deg. The 3967195 is the exact same and is a 180deg. thermostat. Talking to the Cummins dealer today he said that the 190Deg. thermostat dosen't start opening until 190deg. and dosen't open all the way until about 210+ deg. The 180 starts opening at 180 and dosen't opened all the way until 200deg. Running the engine hard today (90-100MPH) with 93deg outside temp, the truck ran about 185-195deg. with the trans temp around 175-185deg. at its max. This was plenty hot enough given the outside temp in our area. Also the 180deg. thermostat will help to keep the trans temp down a little. If anyone has any other questions I will try to help. Thanks, Shrimper P.S. 3 8mm bolts pulled out, put back in and torqued back to 12 ft.lb. Gasket is on the thermostat no other gaskets needed.

 

Yup! And it only takes about 5 minutes with minimal spillage of coolant....

 

I would like to switch mine over to a 180* but the closest Cummins dealer to me is showing to be 75 miles away according to their web site. Unless I can find a source on line it is not worth the drive for me.

 

Hunter11, Call them and ask them to put you one in the mail. It should only cost a few dollars for them to mail it and most dealer are happy to send them. It should be there overnight and they usually have a shipment going out everyday to somewhere. It's worth the diffrence in the temp. I have a question. Dose anyone know when they went to a 190 deg. thermostat. My 1998 1/2 24 valve 4x4 LWB 47RE has a 180 deg. in it.

 

Look like I am SOL on getting a 180* for my 05. I emailed 3 Cummins dealers in Texas today and all three told me my truck calls for a 190* and that is all they have for it or that may be all they will sell me for it. All give me this part number 3954830 which they say is the 190*.

 

Hunter11, I had both thermostats side by side and the 3954830 is the same as 3967195 in every way. You have to look at the inside on the back to see that the 3967195 is a 180 deg. thermostat. Just tell them that you want a 3967195 and if they ask what it fits or what for, tell them a 5.9 liter Cummins, thats all. That is the correct thermostat for your truck. When you take your 190 deg. thermostat out you will see that the 180 is exactly the same in every way. Don't put them down together, you can't tell them apart. The only way to tell them apart is one has 190 and the other has 180 on them in very small print on the bottom side of the thermostat. 97 deg. outside temp here today and it ran 185-190 at 60 MPH and trans temp was 175-180. Air seems to be a bit cooler also. I live in Southeast Texas, and the place that I went and picked mine up from was Smarts Trucks 4730 Washington Blvd. Beaumont, Texas 77707 409-842-5110 Talk to Neil at the parts counter. If you have any other problems let me know and I will pick one up for you and send it to you. With tax it was $30. and low change for a Genuine Cummins Thermostat. Take Care, Shrimper

 

Shrimper, thanks for the info. and I will give them a call.

 

Dropped in the 180 thermostat today, I saw a marked drop in crusing temps. The temp gauge previously set square on the 200 mark most of the time, except when towing. when it was always about the width of the needle above the 200 mark. Now the gauge reads about two needles width below the 200 mark. I would rather run and tow a little on the cool side.

 

Someone help me understand why the truck needs to run cooler. I thought they need to run hot to burn all the fuel in the motor as it's running?? I thought the hotter the better. Mine runs at 199 most of the time and spikes up with hard acceleration.

Jamie