Cooling ??

[tfrane]

Guys (and Gals)

My '91 coolant runs at the high limit most of the time, even unloaded. Every thing is in good shape. Clean and fresh fluid, new water pump, new hoses, and

so forth. I do know that the original radiator design is not proper, but what is

the suggestion? Anyone do anything, have the radiator re-done/re-designed or

something that may have helped this imperficed condition? Sure would like to hear some possible suggestions.





Tim

 

[MMeier]

How old is the thermostat?

 

[Grizzly]

You may need the radiator rodded out and cleaned or replaced.

 

[Leper]

Fan clutch, tstat, clogged fins on radiator. On the fins, so much stuff can get in there and you cant see it. Sometimes you can just pressure wash it from the back side.

 

[KOG]

Have you checked actual temperature with an infrared gun to see if the gauge is wonky?

 

[RWWinslow]

I fought this issue a couple of years ago. . . . the radiator was the major source of the problem - filled up with bugs on the outside and solder bloom / mineral deposits on the inside. You can find a replacement radiator - new - for $200 through a couple of internet web sites - I used JMAC radiators out of Salt Lake City. When I replaced the radiator, I installed a stainless screen (#8 mesh) behind the grille cover - it sits about 2" in front of the A/C condenser. It does not restrict air flow and works by causing the bugs to be cut up into small pieces as they hit the screen wires which means they do not stick their gooey guts into the A/C condenseer core and radiator fins. Any small bug parts that do make it to the radiator or A/C condenser core fins dry up and fall out or are easily washed out.



My fan clutch was also weak and that contributed to the problem. do so me research on the fan clutch and fan before replacing - supposedly there is a upgrade available for the Cummins set up. At the Oregon coast fan use should be pretty minimal - I would think. Finally, these engines had a history of thermostat problems / issues early in life. The thermostat would stick. Get the replacement thermostat from Cummins (use the engine serial number) and follow the instructions.



I have been into the coolant system on the block a number of times - water pump replacement, block heater replacement, and thermostat replacement. It has always been clean and deposit free.



Call me if you have additional questions.

 

[tfrane]

Cooling again

I want to thank everbody for the replies. I've been on this site since '97 (my first truck before the '91) I'll check and repace things now and let you people know the outcome. This is probable about my 4th post in 10 years. THANKS Also,RWWinsow thanks for your teckical information.

Tim

 

[Grizzly]

I want to thank everbody for the replies. I've been on this site since '97 (my first truck before the '91) I'll check and repace things now and let you people know the outcome. This is probable about my 4th post in 10 years. THANKS Also,RWWinsow thanks for your teckical information.

Tim

Good luck to you Tim. I hope you get the problem resolved and it doesn't cost you too much. Let us know what you do.

 

[WCantrell]

Thanks for all the input. I have learned much! Has anyone heard of changes in the design of aftermarket water pumps? The one I removed had a ring on the impellor. (maybe a restrictor?) The replacment did not. Fyi, the replacement came from NAPA.