Engine/Transmission (1998.5 - 2002) Water pump/overheating

[Oliver88]

Having some over heating problems. Going to change thermostat this afternoon. Does not overheat in a non-towing situation. It runs just around 190. Can the water pump be bad with no signs of leaking? I took off the radiatior cap and didn't see any signs of circulation. Maybe the thermostat wasn't open at the time or maybe it is stuck shut. I cleaned the radiator good yesterday with no difference in temps. It was really dirty with an oily film. The fan clutch seems to be working. Any ideas on the water pump?

Thanks,

Greg

 

[Steve Campbell]

Start out with the simplest things first....

I have found that it is pretty hard to power wash the radiator in the truck.

The thermostat is easier to get to than the water pump... thus I would replace it next, as you suggested.

I have only had one water pump fail in my life (without showing signs of leakage) and on that one the impeller was spinning on the shaft.





I guess, I want to say I think you are doing things in the proper order.

 

[Oliver88]

I used an air conditioner coil cleaner to clean the radiator. Used a garden sprayer with a 45 degree nozzel to spray between the radiator and intercooler. Really works well. Thanks for the advice.

Greg

 

[rashwor]

It does happen...

I think I would go with the thermostat first. It is the simplest, cheapest possible cause. The go bad more often than the water pumps. I think you are doing things in the right order. You may want to get the 180* thermostat for the Cummins. Is your old thermostat a 180* or 190*? I am planning on changing my coolant this summer and will change the thermostat when I do. I don't know which one I have now, but I will go back with a 180*. I am thinking I might change the water pump at the same time, but money is tight. The truck currently has 141,000 miles on it. In my old '92 which now has 230,000+ miles, the water pump started seeping from the weep hole at 180,000 miles. New pump, problem solved.



I have seen one water pump go bad and cause overheating without leaking. It was on a 1975 John Deere tractor and happened two years ago. Just to give you an ideal of how much this tractor has been used, the empeller blades were worn slick off the pump! I could not believe it! Generally, John Deere pumps will leak and the front bearing will go out long before the empeller shows any wear. New pump installed and no more overheating problems. Thermostat was fine.

 

[Oliver88]

If I get that far does anyone know the cost and part number of the water pump?

Greg

 

[Thomas]

4429698 SEAL, Water Pump To Front Cover $1. 60



5010964AA PUMP, Water $115. 00





Prices are list.

 

[Oliver88]

Overheating problem seems to be fixed. Replaced the thermostat with a 180 degree thermostat. Temp guage runs considerably cooler. It was just above 190 most of the time without towing. Towing will be the real test, but I believe it was a thermostat problem. Thanks for the advice guys.

Greg

 

[PRout]

Just curious if the overheating problem while towing was solved by changing the thermostat.



Mine recently changed where the temps are fine until towing heavy up a grade, then the temp jumps to critical fast. Have lots of power left but have to crawl up in 2nd gear & turn off the A/C & turn on the heater to keep it under control.



I suspect the thermostat as well, but this one is the 180 from Genos that I put in 2 yrs ago, not the original. I havent heard of them going bad. Can hear the fan running so that probably isnt the problem. It always chirps on warm shutdowns.

 

[A Johnson]

The little plate thet shuts off the bypass passage could very well be broken off of your t-stat. The last t-stat I bought had some changes from the original stat in that the part that blocks the bypass passage is now made of brass and looks much more robust. I would start there as its very easy.



A Johnson

 

[ben_ak]

Just to add to the water pump diagnosis, water pumps do not always leak when they fail. I am a Subaru tech and I would say on Subarus, probably 95% leak, most make noise when let go long enough, but sometimes, rarely, no noise or leaking is present.

 

[rashwor]

Had water pump...

go out on one of my JD tractors. It started running hot, but the pump never leaked. Removed the water pump and found out the impellors were wore completely smooth!:--) It wasn't moving any water. Replaced the pump and cool as a cucumber now.



It could also be the thermostat... start with the cheap stuff and work your way up in price. Thermostats do go bad and it is not unheard of for them to go with as little as 2 years on them. I have found it to be a good rule to change them when you change the coolant (in my case, every 2 years at a minimum no matter what).

 

[Steve Campbell]

this is good advise for troubleshooting any problem....

"start with the cheap stuff and work your way up in price. "