Well I took the truck out for a little trip this past weekend and I noticed running it hard up the mountians it got a little on the warm side. The truck runs fine all day long in 110 degree heat but up in the mountians probably crusing about 80 it got pretty toasty. It would cool back down when I would be going down the mountains also. I am wondering if this is normal. I wasn't towing anything but the truck is a flying brick because of how big it is. Was I running it too hard or what? Do I need to flush the cooling system?

Thanks

 

It is normal for the diesel to get quite hot when you pull steep grades. The gauge should be in the very top quadrant when it is really working, and it will not hurt a thing.

Keep in mind that you are making real big horsepower, just like the big trucks, but have a radiator that is less than a quarter of what they use.

You will not hurt anything by getting the coolant as high as 300 degrees if you use a good one like Evans Cool, as long as you have top quality synthetic oil and keep an eye on the EGT and do not run it over 1250 degrees F for sustained periods.

Just do not cold shock the engine by letting it drop the coolant temperature too fast on the downhill grades. These work just like an airplane, and controlled temperature swings are what keep the engines living forever.

 

Every time I hear not to let an engine cool too fast, I've always had the same question. How are you supposed to do that? It's not like you can keep your foot into it as you're cresting the hill. If you don't let off, you'll rocket down the hill and pile it up. How does one control the EGT and engine temp from decreasing too fast?

 

Thanks, I just was not too sure what to expect because I have never taken my truck anywhere like this. It took a little bit but it did cool down and it wasnt too fast either.

 

If the road was curvy and steep keeping your tranny TC from locking up it could have also contributed to your high coolant temps. There is a coolant/tranny cooler on these rigs.
A/C will do it too. I basically ignore the gauge unless it gets into the red, never has even on 14% grades, 100° days pulling a trailer. Gets close though.

 

My was locked, how do I keep it from locking? Egts were fine so I didnt bother with changing gears.

 

press your od button

 

This will only keep it from locking in 4th, it will still lock in 3rd.