Engine/Transmission (1994 - 1998) Revised Cummins T-stat numbers?

[Ben Rumson]

Need part numbers for the new CUMMINS REVISED thermostats



1995 12v'er in 180*:______________________



1998. 5 24 v'er in 180*:_____________________

1998. 5 24 v'er in 190*:_____________________



I called a local Cummins shop to get them and they wanted the engine numbers to look them up.



I have mine, but my Dad's rig is in Wyoming and I want to get it for him without him knowing (otherwise, he'll want to pay for it).



Any help you be appreciated. Thanks.

 

[Jeff H]

Is the revised one a non cycling t stat?

There is a part # listed in one of the TDR issues. Will have to look back a few years.

I have a non cycling t stat. Works good.

 

[Jammar9082]

Ben: I don't know what "new Cummins Revised thermostat" means. I have a number that was the latest number on 24 JUL 2001. This may or may not be the latest revision. The number I have is Cummins P/N 3934373 equal to DC P/N 3928499.



I thought I remembered more recent information on the thermostat than my 2001 date but do not find anything in my part number listing.



I will be interested in the other responses as I need to change my thermostat. It wants to stick closed sometimes. The current thermostat is a NAPA changed out in Mar 2000. The Napa P/N was 370-180 and cost $9. 00. This thermostat does cycle up and down.

 

[illflem]

I tried the new revised thermostat it stopped the cycling but ran way too cold. Ended up with the 190° Stant stat from Napa for $9 also. Still cycles but not as bad as the stock and at least warms ups

 

[Ben Rumson]

Non-cycling T-stat at last!

Originally posted by Jammar9082

... The number I have is Cummins P/N 3934373 equal to DC P/N 3928499.



I will be interested in the other responses as I need to change my thermostat. It wants to stick closed sometimes. The current thermostat is a NAPA changed out in Mar 2000. The Napa P/N was 370-180 and cost $9. 00. This thermostat does cycle up and down.

=======================================



Jammar9082, Thanks for the information.



NEW T-STAT WORKS GREAT . Very consistent 170* unloaded and does not fluctuate ANY! And, the cab heater still "cooks". Couldn't be happier



I called Cummins with the 3928499 number and they said it was their most current number for the t-stat. Neither 1-800-Diesels, or Cummins Intermountain, in SLC, could verify any "re-design", but they did confirm the 180* setting. The 180* is supposed to respond slower - thus slowing down the hugh rush of cold radiator coolant into the block (and the constant temp cycling that it causes). The result is a more constant coolant temp.



Parts - all Genuine Cummins Parts and Numbers from a local Cummins repair shop. These are NOT Chrysler part numbers):



T-stat - 3928499 (Date on box: 20-Nov-02, Origin: MX, Genuine Cummins Parts) - $18. 99.

O-Ring Gasket - 3925466 (Radiator side) - $0. 75.

Housing Gasket - 3927305 (sleeve-style, thicker, with recessed groove on one end) - $2. 88.



True, our Cummins engine tends to "tollerate" the temp fluctuations with the older, stock t-stats AND many members have quite high miles with their original stat... BUT for under $25 why tempt fate with your head gasket? This is IMO, an ounce of prevention.



I wish I had replaced my stock stat much earlier. Have yet to pull a load with it, but trust it will perform equally well.

 

[Extreme1]

Hmmmm... .



I was just thinking about this tonight. I'm in the same situation Bill was. I replaced my good old "swinging" stat when I should have replaced the fan clutch.



Where on the temp guage did your improved Cummins stat run, Bill?



Anyone have an old "swinger" they want to send me?

 

[Ben Rumson]

I probably won't ever use my old one again, but I'm going to toss it in my bed box (with my spare fuel filter) in case I need it when I'm on the road.



Also, one more part to have around in case a traveling TDR Member needs it after hours and they break down in my neck of the woods.



Someone else have one they could send?

 

[illflem]

My improved Cummins stat ran a steady 140-150 in the winter, never gave it a chance in warmer weather. The stock stat cycled between 140-190. My $9 Stant cycles between 170-190 year round. These numbers are assuming the lower hash mark is 140 as the only number on my gauge is 190.

 

[Ben Rumson]

Originally posted by illflem

My improved Cummins stat ran a steady 140-150 in the winter...

At 150*, I would have pulled it out too - not near warm enough.



My new one runs at a solid, steady 170*. Cab heater works great.



Perhaps (apparently) you got a defective one.

 

[Extreme1]

Originally posted by illflem

My improved Cummins stat ran a steady 140-150 in the winter...

Mine does year 'round. With the radiator covered and 35+ degree weather, it'll go a little higher but not much. I'll go get the NAPA one tomorrow. Thanks Bill!