Engine Temperature

[Barbieri]

What is the normal operating temp for a 98 2500hd ram 24valve engine? I see 190 for local driving. If the air tem is 85 deg and your running 70 - 80 mph say 75mph for 30 min. I see a temp around 200 - 220. When I slow down it goes down. I was under the impression that high temps on a diesel is good, and low temps doesn't allow the fuel to burn correctly. Please show me the way. This is my 1st diesel and its a different ball game. The owners manual mentions high temps. I am not use to seeing temps around 230.

 

[Prairie Dog]

I never had a second gen truck like yours (went from first gen to 3rd) but from my experience temps of 230 are normally only seen when towing up steep grades. It may be time to flush your cooling sytem and replace the thermostat. ALso you may wan't to check the fan clutch operation as they tend to get weak with age.

 

[MCummings]

Originally posted by Barbieri

I was under the impression that high temps on a diesel is good, and low temps doesn't allow the fuel to burn correctly.

The temps you are talking about are Exhaust Gas Temperature's. If those get too cold for too long, that's bad, less than 300*F, for a few hours, is bad. Anything over 1,250*F is bad, bad as in, melted stuff, but when does melted stuff happen? Not sure, but damage will happen at 1,450, I've had my truck to 1800* a couple times, and 1500* Daily, but, after 35,000 Miles of doing that, I pulled my head (truck has 120K) and I found the head to be cracked beyond repair, but that could have been caused by the blown headgasket, or atleast worsened.



High water temp is bad for hoses, all rubber and plastic material under the hood, and MPG.



Some members reported better mileage when running a 180* thermostat, and the fan clutch kicked in alot less.

Temperatures over 190* aren't good. Sounds like you have a stuck or broken thermostat. Maybe even a fan clutch that has "sold the farm".



When your temps are 220*, does it sound like there is a tornado under your hood? If not, I'd suspect a fan clutch.



Hope this helps you.



Merrick Cummings Jr

 

[MCummings]

Fan Clutch?



Try this thread.



https://www.turbodieselregister.com/forums/showthread.php?s=&threadid=78413



Merrick Cummings Jr

 

[CumminsPower98]

Another thing to check is for bugs in the radiator. I have seen many radiators plugged so bad with bugs that they overheat. Good chance this is not the problem but something to think about. Driving empty on the hottest of days my truck never even reaches 190º. The hottest I have seen was 190º on a hot day (over 100) pulling steep mountain grades with the A/C on.