I bought a 2004 dodge ram 1500 about 3 months ago, i knew it would need some work but im about at a loss right now. It has a 5.7 hemi in it and i have done alot of work to it already, but my issue is that my truck will not stop redlining... (Overheating) it does it mostly when i am in park idling or mostly stationery like in a drive thru... Within about 2 1/2 mins or so my truck will go from normal temps to redlined out. It does get hot occasionally when i am driving but once i goose the gas a bit the temp will begin to drop. I have already replaced the thermostat, thermostat casket, upper and lower radiator hoses, the radiator its self, the radiator cap, i did a radiator flush on it... Today i just changed the water pump and yet still nothing has changed. What next bc i am about tapped out and beyond frustrated. Im being told by a friend now to do the damn fan clutch... But at the same time im sick of guessing and assuming what may be the issue... Any ideas? (Oh and there is not a blown head either... Oil is dirty but no water or unusual contaminates)

 

Hi Steph. How is it on the freeway or similar steady highway driving? If it is okay your friend may be right on the fan clutch. When in slow traffic or a drive thru the fan clutch will engage to draw more air thru the radiator to assist cooling the engine. On the highway there is plenty of air going thru the radiator and the fan clutch is not needed.
Find a friend with a live scan tool that can read the engine operating temperature in various driving conditions and simulate your overheating issue. This may rule out a possible faulty temperature sensor causing your gauge to redline. Good luck.

 

From your description, the fan clutch should have been your first event. If it only runs hot when it isn't moving, the fan clutch is not spinning the fan fast enough to pull sufficient air through the radiator. If it was the thermostat, vehicle speed would not matter. Stop throwing money at it and think the process through.

 

+3
fan clutch seems reasonable. make sure all the fan shrouding is in place.

 

To add to this, the fan clutch and water pump should be replaced at the same time.

 

Defiantly the fan clutch. You can test it like this. When you start it first thing in the morning. You should hear the fan making noise. If not it's bad. Usually at that point I take a stick or something and try to stop the fan from spinning when the motors still running. If you can it's defiantly bad. The last time mine went out I said f'it and converted it to an electric fan set up. I wi never go back to a fan clutch again

 

Ok so since all of this i have replaced the fan clutch and i put a bipass in the lines that run to the heater core bc apparent it needs to be replaced... Its still getting hot. #deepsigh

 

Are you 100% sure it is actually overheating or are you just getting an indication on the temp gauge? I do not see that you have replaced the temp sensor. You may be getting an erroneous indication. If not the temp sensor, it may be a wiring issue.

It sounds like you have changed every component in the cooling system. The only other thing I can think of would be a buildup of scale inside the engine restricting coolant flow. But I'm betting it may be a faulty temp sensor.

 

I have this same problem. It started when I heard loud pop sound and immediately started overheating like crazy. I changed out the thermostat, water pump, and fan clutch. I keep my resovoir full at all times with water. it will go thru coolant faster than I can afford to replace it. I believe I have a partially blown head gasket that I will be replacing this summer. Not sure if this helps at all, good luck

 

Did you ever get this sorted out? ..... Kind of did the same as you did, and never got a handle on it.... Kept boiling over in the coolant reservoir..