kw900l Cat c-15 625hp overheating

I would recommend having the aftercooler pressure tested to start with.

 

Is the fan coming on?

 

Turn the fan on at the bottom of the hill before it starts to heat up, then just take it easy going up the hill, you don't have to be the first one to the top.

 

Is it overheating meaning the bells and whistles coming on or is the guage reading high temps.

 

My Detroit was doing it and I couldnt find it. I checked both the cooling system and for boost leaks.

When I replaced my stock exhaust with the Donaldson 463 it stopped instantly. Apparently the muffler was broken up internally.

 

Danny Boy: You don't reference anything about temperatures before you hit the bottom of the hill, nor mileage on the engine. The fan is usually set to come on 15-20 degrees after the thermostats open up. There should be 190 degree thermostats in the engine. If the thermostats are slow to open up under normal conditions then they may be hanging up in the seals. The only way to verify thermostat operation is watch your temp. gage when you first start the truck up. Watch to see what the max temperature is before is stops. That should be where the thermostat first opens up, sometimes they just stay there or cool down about five to ten degrees. I have had trucks overheat if the thermostats were sluggish in opening fully. This prevents proper cooling operations. The other thing is to electronically verify the gage and engine temp sensors are operating at same temperature. Finally follow the advise up above and manually turn fan on at bottom of hill to prevent losing cooling capabilities in the middle of the pull.

 

You also need to check the water pump for output pressure. The impeller could be spinning on the shaft and limiting the cooling capacity

 

i have a 5DS 15.8L i've had it 3 years for the first 2 you couldn't get it hot fan never came on (i rarely get over 85000 ) i did turn it on a few times at around 200 and temp would drop to 180 fast . for the last year it runs closer to 195 all the time , and even with fan on at the bottom of an ok pull it will go from 190 up to 210 befor the top ,even with fan on 106f out just running 18-20 psi boost it will start to heat up . never did it befor . i am in TX i do pull a wagon and yes its hot but it seams odd

 

x2 I've had 2 do this.