Engine/Transmission (1998.5 - 2002) Cummins Thermostat Part #?

[Nate]

I bought a theromostat from the Cummins dealer and went to install it today.



Well I realized that the thermostat I got is a 180*. I checked on my truck and it says 180 195 on it... so I'm not sure it that's a 180 or a 195?



Am I correct that 195* is stock?



I have part # 3967195 for the 180* thermostat. Would anyone have the part number for a 195*?



Thanks

Nate

 

[Nate]

Ok I did some more reading and I'm guess that 195 on the factory thermostat is the part # or something, since it would be either a 180* or 190*



The 180* is part # 3967195 ~$30

The 190* is part # 3946849 ~$60



From what I understand, after 2000/01 CTD trucks got the 190* for a bit better heat, though Cummins recomends the 180*, which is standard in all of the engines.



So... I'm gonna install this 180* one and see what that does.

 

[JMLambert]

Mine was a 180. .

 

[rowilson]

I just did the anti-freeze change and thermostat on my truck and it used a 190 per the build/serial number on the timing cover. The difference between the 180 to the 190 was surprising. The 190 was built a little heavier duty than the 180. I bought the 190 and yes it was $63. BTW, I changed out the Fleetguard ES Compleat EG.

 

[Nate]

If the heat still sucks with the 180* I may buy the 190*. Just crazy $60 for a thermostat

 

[Nate]

Interesting info about temps from Evans coolant:



Diesels run most efficiently at approximately 200*. A 195* thermostat will start to open at approximately 165*-170*. The Powerstroke has such an efficient cooling system, that this low flow when the thermostat is slightly open is normally enough to keep the engine cool. The downfall to this is that the engine -- when our trucks are not under load --never begins to reach its optimal operating temperature. Our 203o thermostat begins to open at 185o. This brings the operating temps up from about 170o to about 185o. This is closer to the operating temperature range that is preferable in our trucks for optimal efficiency.



When our trucks are under load and are producing higher combustion temperatures the 203o will allow the engine to run even closer to its optimal operating temperature. If the truck is under load and reaches the 203o setting, the thermostat is then fully open. This means you are at the maximum coolant temperature that the truck will reach. Your maximum temperatures are only a few degrees higher than in stock configuration, but these are degrees that you want for better performance. The best benefits come when the same truck is under a light load and would have a hard time reaching this optimal temperature. As stated above, you will never reach this optimum temperature with the stock 195o thermostat. The end result of installing the 203o thermostat should be slightly better fuel economy, less smoke, and maybe a few extra "ponies" to go along with it.







Why does the same not apply to the Cummins engine?