My thermostat was stuck open causing the truck to take forever to warm up to operating temp.

Had the system flushed and new coolant installed, and then I installed a new NAPA 190 degree thermostat.

I am amazed at how much better the truck runs, with just a thermostat change. I mean, it's not a subtle change: Truck now warms up quicker like it should, sounds much better, accelerates better, just a whole lot better all around.

What is it that makes such a difference in engine performance? Is the computer system that dialed in to operating temperature that it adjusts air/fuel, etc. to make that significant a difference in performance?

Sure love the results....just hoping to understand better why they're so good!

 

the cummins is programmed to run its best at operating temps which is 180 and higher, i don't know what the limits are! i may be wrong about 180 degrees also ...EPA has a lot to do with it!

 

02 requires a 190...diesels like to run hot, better combustion etc. Guys a lot smarter than me got it figured out so I stick with the specs given...

 

FYI - most recent thermostat part number issued by cummins

P/N 5292742
$42

 

Diesel engines operate off of the heat generated by compression within the cylinder stroke. If the heat retained in the cylinder head is too low then combustion will be incomplete and everything else suffers. This is why most diesels have some sort of cold weather starting aid like grid heaters or glow plugs. For most diesels they cant crank fast enough in the frigid weather to generate enough compression heat when the engine is cold.

 

Well, with a 12V you would have to take care of not beating on a cold engine yourself. Since the 24V uses electronics it will keep you from A: beating on a cold engine and B: from getting good fuel economy (for the price of high emissions) from a cold engine.
The reasons are as stated by KATOOM and johnh..

 

So many things can depend on this singular issue. You can also do harm to your alternator too believe it or not. Many people in cold weather start the truck in the driveway and let it idle for a long period of time. Not a good thing on the diodes in the alt as the electrical system cycles the grid heaters on and off repeatedly during that idle time hammering the charging system. Many other better options to get the truck up to operating temp including but not limited to just driving it gently for the first ten minutes. Once the charging system starts to take a hit and wear out torque converter shifting problems will result along with a host of ECU/PCM problems. All from MR FREEZees....These trucks run great but do need to be a well oiled machine to make the owner happy long time.

 

Is this for 12 valve or does it matter?
Where can I get one?

 

And thank you for this part number. Exactly what I was looking for 👍🇺🇸😎