smog2001

Recently my truck started to have some over heating issues while towing my 13000lb toy hauler. At first, the struck would hit 240. I replaced the thermostat and thought the problem was fixed. I purchased the thermostat from Cummins. I took the trailer out this weekend and the truck would fluctuate between 188-210. I do not remeber the truck ever running this hot before.


Could something else be failing?


Is this normal? I may just be worried about nothing. Thanks in advance for the imput.

RLee2500

My temp's while pulling run about 180-190, and about 200 on the hills, or about 1 needle's width above the 190 mark if I am really working it. I have never seen my temps get any higher than this. This was how the truck behaved a few weeks ago in 98 degree heat, pulling my TT on a 7% grade that is about 3-4 miles long. I am not pulling quite as much weight as you are though. Hope this gives you an idea.

mwlu711

the radiator gets clogged about every 100000 miles due to the crank case breather beeing right behind it.best thing to do would be to pull the radiator and use some good degreaser to clean it and that should help a lot.

2500

you need to first determine if truck is really running hot... or temp sending unit/gauge is wrong.

let's assume truck is really running hot and not the temp sender.

1. first thing you want to do is make sure it's not clogged externally like another poster indicated.

2. you've already changed out thermostat, but you could have gotten a defective one from cummins. it needs to be swapped out and/or ran without a thermostat to see if that cures issue.

3. need to pressurize your cooling system with a system tester. to see if your system holds pressure. small leaks can be taken care of using "bars leak". use it and nothing else. tighten all clamps first. if you find any hose failure. I like replacing all hoses that's the same age.

4. test radiator cap w/system tester and/or replace radiator cap.

5. test out fan clutch for viscous drag of coupling. if fan clutch is slipping, than can cause over heating too.

any of the above can cause overheating and/or appearance of.
when temp gauge indicates truck is running hot, spray cold water on radiator (not motor) this should quickly pull down engine temps safely and be reflected immediately on gauge.

radiator can be clogged internally too. if all of the above is done and CTD still runs hot, then it's time to look internally at motor and/or radiator clog.

dssimecek

Those temps don't sound unreasonable for where you are, the hot southwest, and load you tow. Do the checks of the cooling system that are suggested. If you have a IR temperature checker, check the coolent temperature at the thermostat housing. It should be about what the temp gauge reads.
With the load you tow an IR temp checker is good to check tire and brake temps.

smog2001

Truck has 84,000 so I guess that is close enough to pull the radiator out and clean it and flush the entire system. Thanks for the reply

smog2001

Thanks for the great response. I am not sure how to check the clutch fan though. Could you or someone explain this a little further for me. Tonight I will pull out the radiator and clean it.


Thanks,

AndyMan

I recently pulled my radiator and cleaned it b/c of the same type of thing. The radiator was absoloutely filthy! Cleaning it fixed the problem.