Here is the deal. My 03 has 175K on it and about 4 months ago the water pump went as it started spewing radiator fluid and spraying it all over the place.
I replaced that, serpentine belt, thermostat. It ran okay for a couple months and then started leaking again and running hot (220ish on factory gauge). Any given day normally never ran above 190ish on the gauge. Leakage drained out the overflow completely. Refilled that and found that the top radiator hose needed to be changed due to minor cracking and it looked as that is where my new leak came from. Did so.

Now I have no leaks but the truck **** near over heated at 240 on the gauge. Almost red lined. I initially assumed it was the radiator/hoses but no leaks and overflow is plenty full.

What now!?!?

I then rolled the windows down and found it to idle high, (It's and automatic) and I found that when it shifts from first to second and so forth it revs higher than normal. As I continue to press the gas the revs get louder until finally it will shift and the temp gauge will then come down a bit but will repeat every time it goes up in gears. The RPM's never go out of whack, just the temp.

I know it is way past time for me to change the tranny fluid and so if I do this; will it stop the reving AND over heating? Or could it be something else in the radiator system?

Any help/direction would be greatly appreciated. Is it time for a new Cummins?

 

Radiator cap? Head gasket?

Maybe could be the radiator is dirty too.

Just for goofs, did you re route the belt correctly? Maybe water pump is spinning backwards.

Good Luck!

Carey

 

fan clutch working

 

Well I had a shop do the pump, thermostat and such. I can only assume they did it right. I brought it back to them on the second leak thinking they did something wrong and that is when they found that the top hose needed replacing and as the tech and I talked it was a simple fix and so I did that myself.

As for the radiator being dirty... they changed the fluid the first time and I did when I changed the top hose because I wanted to make sure I had the right amount of 50/50. When I did it it came out fairly clean so I do not think that is the issue.

Thanks though,
Anything else to check?

 

Is that an easy check?

 

You wouldnt really know. Maybe take the radiator to a radiator guy and have him clean it. 7 years, they can get pretty dirty. Aluminum is has to be clean to transfer heat well.

I tow with mine and flush it with the chemical stuff every couple years. Makes a difference in its cooling everytime.

 

I guess one other thing is that when the truck is running I can feel A LOT of hot air blowing from the fan to the ground underneath it. To the point I can be a couple steps away from it and still feel it. Is that normal?

I am grasping at straws now, I know.

 

There's also a possibility of air in coolant.

 

How do I bleed the air out?

I have more than the max fluid in the reservoir and popping the radiator cap, there was fluid to the top.

The fan moves freely and does not have any real give to it, thus making me believe the fan clutch to be working properly. I see no fluid drain from there.

 

If your fan clutch is operating correctly you should be able to turn the a/c on notice a very audible roar from the fan when it engages. I had my fan clutch go out one time but I was also going down the highway so I had plenty of air moving through the radiator. It was only after I came to a stop and the a/c was blowing warm that I realized my problem.

Make sure you have good circulation from your water pump also.

 

When I turn on the A/C I do hear the pop which is the damper closing and then the A/C runs cold even at the high engine temps. I turned it off though to assist in trying to cool the temps but did turn it back on again and it again ran cold.

Thanks y'all for the help.

 

Ask the shop if they used a genuine Cummins thermostat or a "will fit" part. I have read several threads about our engines needing to use the Cummins thermostat. When I changed my coolant I took the hose that feeds the heater core off to "burp" the air out. I still had a little air in there, but it got most of it out, and the rest came out on it's own with normal driving over the next couple days.

If the trans is slipping at all, it will also cause the truck to over heat.

 

I would suggest you clean the outside of the radiator. Its difficult to get a pressure washer spray directly toward the fins of the rad due to the proximity of other coolers so taking the rad out is the most effective way. I had an unexplainable heating problem too and you wouldn't believe how many bug guts I washed out of the thing.

 

take a hose and spray the inside of the radiator they get jammed with bugs and such just keep rinsing it. dont do it when its hot there is a thread on here somewhere where a guy pulled his out and it was really dirty. i just spray mine once in a while with a hose. also make sure the radiator is full, after a flush it will be low sometimes.

you could have air in the line somewhere i dont know if these trucks bleed it on their own?

the fan clutch could be broken?

the trans could be getting really hot and not allowing the coolant to cool down all the way?

rad cap could be bad, water pump could be bad, thermostat, you could have a head gasket issue. check all the fluids in the truck to make sure they are not over full! also

 

I will go back to the shop an see about the thermostat when they open on Tues.

I will try cleaning the outside as it has never been cleaned and is full of rocks, bugs, and gunk.