04’ cm870 coolant temp high

[Redland1]

I have an 03’ International 9900I with an 04’ cm870.Coolant temp will creep up to 200F at idle and just hold their most of the time and others it will go up to 210 and then kick the fan on.Going down the highway it will creep up to 200-204F and hold it there most of the time or keep climbing to 210F where the fan kicks on.This truck would run down the highway at 180-184F loaded and the temp would only climb when climbing steep long grades.The temperature increase started last summer while drinking but the increase at idle started this spring.I went ahead and changed the thermostat while replacing my radiator when it got a hole in it and water pump as well.No change.The new radiator started leaking as well so I had the old one repaired and no change.I did change the ring when I did the thermostat.What could be causing this?

[Rawze]

coolant temp is supposed to be regulated to 185-F.

did you replace the little brass ring in the bottom of the thermostat housing?... that is typically what causes temps to run higher than normal. Maybe it got damaged?.. or was not installed so well?.

could also be clogged A/C condenser, or clogged CAC with dirt. etc.. not letting enough air flow.

[Redland1]

(06-02-2023 )Rawze Wrote:  coolant temp is supposed to be regulated to 185-F.

did you replace the little brass ring in the bottom of the thermostat housing?... that is typically what causes temps to run higher than normal. Maybe it got damaged?.. or was not installed so well?.

could also be clogged A/C condenser, or clogged CAC with dirt. etc.. not letting enough air flow.

I did replace the brass ring with the installer that’s made for them.Also recently replaced the condenser.I’m going to start with cleaning the condenser and see if that helps,if not I’ll order a new ring and reinstall.Thanks Rawze.I’ll keep y’all updated on what I find.

[Redland1]

Blew out the Intercooler and radiator out real good and no change.Wanted to mention that oil temps going down the road are 2220-225 and climbing a steep hill it’s 235.

[Bengy88]

I had a truck a few years back that was doing something similar to this and it was actually sucking the radiator hose almost shut. It may be something you want to check out. Does the temps drop immediately after the fan kicks in?

[Redland1]

(06-15-2023 )Bengy88 Wrote:  I had a truck a few years back that was doing something similar to this and it was actually sucking the radiator hose almost shut. It may be something you want to check out. Does the temps drop immediately after the fan kicks in?

Yes the temps drop with the fan.How’d you figure it out

[Bengy88]

Held the accelerator in the floor and had the hood open I could see it from the drivers seat. I can’t remember what make the truck was, it was supposed to have a spring in the hose from the factory to hold it open and someone had taken it out. I sent you my info. Shoot me a text and I’ll do my best to help you figure this out.

[Bengy88]

Before I say this I may be thinking completely f*****. But since that engine should be regulated at 184 shouldn’t the ecm be requesting the fan to kick in way sooner than 210 degrees? I’m pretty sure a cm2350 kicks in at 210ish….. but an 870 should never see temperatures like that before the fan comes on….. maybe I’m wrong and if I am then someone please correct me like I said sometimes my brain gets me but I think I’m thinking right.

[Rawze]

(06-15-2023 )Bengy88 Wrote:  Before I say this I may be thinking completely f*****. But since that engine should be regulated at 184 shouldn’t the ecm be requesting the fan to kick in way sooner than 210 degrees? I’m pretty sure a cm2350 kicks in at 210ish….. but an 870 should never see temperatures like that before the fan comes on….. maybe I’m wrong and if I am then someone please correct me like I said sometimes my brain gets me but I think I’m thinking right.

thermostat keeps it at 185-f.. but the engine fan does not kick in til it gets to 215F for most trucks.