I recently bought a durango that was sitting in his dads backyard. I was told of all the problems it had and fixed them all except this overheating problem. I was told the heater core leaks so his dad had bypassed it for a temp fix. I hooked it up and put some bars leak in it and it seemed to have fixed it for a few hours until I got home and shut the car off. It sounded like water was flowing everywhere and there was a puddle of antifreeze on my passenger side floor. So I bypassed the heater core again. It stopped overheating until i got to my friends house and we left for town it was back at 260 so I pulled over and put antifreeze in the reservoir. It worked fine until I went home to get money to pay a friend to put my heater core in and it overheated in about 2 mins when I started driving down the road. So now its sitting in my driveway and I have no idea whats wrong. From what I can see the water pump isn't leaking and there is no antifreeze on the ground but my reservoir is empty again. Any ideas? Sorry for the lengthy paragraph I'm not a mechanic in anyway and I tried to be as specific as possible to help diagnose the problem.

 

Sounds like its going through the exhaust, how does it run? What does the exhaust look like, cause if its not leaking and its been over heated that many time sounds like head problems. Sorry for the bad news but thats all I can think of.

 

Do you have a 4.7 engine? If so you must "burp" the engine. Raising the front end a lot higher than the rear and run the eng till it comes from the cap and add the remaining coolant. Keep in mind this only works with the 4.7 eng only.

 

It'll help if you post the details about the truck.

Like the previous poster said, if you have a 4.7 you need to burp the system. An easy way to do it is to open the radiator and fill it to the top, then squeeze the upper radiator hose slowly to force out the air. Refill the radiator as needed, then close everything up, fill the reservoir to the "full cold" line and start the truck. That should get enough of the air out to stop the water pump from cavitating. Let it warm up so the thermostat opens then let it cool down again. Check the overflow bottle and add coolant as needed.

If you're still losing coolant / overheating after this then you either have a leak that your not seeing, or a bad head gasket / head that's allowing the water to enter the cylinders. Take a good look at your oil, if it's contaminated with water then chances are a gasket is gone.

Bob

 

+1 Bob