Rawze.com: Rawze's ISX Technical Discussion and more

Hi guys,

Last summer I purchased a 2010 International ProStar with a Cummins ISX15 that has been converted into an RV hauler to pull my 5th wheel camper. This is my first class 8 truck, so I'm a bit of a noob. Have a couple questions...

- I noticed that it takes a long time for the coolant temperature to rise. Idling wont even get the temp gage to move. Now that the temperatures have dropped, even driving it for 30 minutes barely gets the gage above 140 degrees. Is this normal or do I have a thermostat issue? What should the normal operating temp be?

- I also noticed that the fan rarely kicks on, especially now that its cold outside, but when it does it's a very loud and annoying roar from under the hood. Is this normal?

Thanks in advance.

Danny

Sounds like thermostat needs replaced. May be stuck open.

just for reference...

It takes my truck a good 20 - 30 minutes of just idling if it has sat a few days in cooler weather (40's F) before it gets to its regulated 185 degrees.

this is not implying there is nothing wrong with yours... you need to replace the thermostat and the brass ring in the bottom of the housing if it is more then a few years old, simply for safety of the engine if there is any question or doubt. It is cheap insurance.

Hi Rawze,

Is your fan also pretty loud when it kicks on? Just want to make sure that doesn’t indicate a problem with the clutch or anything.

(01-12-2021 )Rawze Wrote: [ -> ]just for reference...

It takes my truck a good 20 - 30 minutes of just idling if it has sat a few days in cooler weather (40's F) before it gets to its regulated 185 degrees.

this is not implying there is nothing wrong with yours... you need to replace the thermostat and the brass ring in the bottom of the housing if it is more then a few years old, simply for safety of the engine if there is any question or doubt. It is cheap insurance.