2002 Dodge Truck Overheating at high speeds

MORGAN_JARED

MEMBER
2002 DODGE TRUCK
V8
4WD
AUTOMATIC
131,000 MILES

My truck started overheating a few weeks ago. I took it into a mechanic, where eventually the radiator, hoses, and thermostat were replaced. The radiator had been about 80% clogged with an orange colored gunk. I got it back and instead of overheating it just ran hot at higher speeds. I took it back and after telling them the heater also was not working, they flushed the heater core, which was also very clogged. The heater and the truck seemed to work fine for a few days but started running hot again. Currently at 70mph the gauge will reach 3/4, at 65mph about 5/8 and 60 just above half. Once I slow down to about 50 or below it goes back to normal. Also the heater blows warm, but not hot. I see no apparent coolant leaks and radiator fluid as well as oil is full. What could I be missing here?

1 Reply

MHPAUTOS

MECHANIC
31,937 POSTS

Hi there,

With the elevated engine temp you would expect the heater to be hot. So I would re flush the heater core and check that the heater tap is fully opening. As for the truck over heating, was the radiator removed and the tanks taken off, or just back flushed with a hose? If so it could still be blocked. Also check between the radiator and the A/C condenser (if A/C fitted) make sure that it is not clogged with leaf litter. Clean the A/C condenser fins as well as the air for cooling has a lot to get through before it starts to do any good.

Mark (mhpautos)