I have been having an issue with my 98 Dakota 5.2V-8 overheating. I have replaced my thermostat, radiator, water pump, fan clutch, and upper radiator hose. I have noticed that after my truck overheats about 30 minutes after I shut the engine off I look under the hood and the upper rad hose is completely compressed. When I check my truck after sitting all night the upper hose is decompressed. I really need some help this is my daily driver and it overheats if I drive it over 20 min or so.

 

Replace the radiator cap.

 

Even if the cap is only a few years old? I replaced it to a 7lbs cap

 

The cap has a vacuum relief valve that opens as it cools down and lets it draw coolant back into the radiator from the overflow tank. It sounds like yours isn't working, collapsing the hose from the vacuum instead.

To be honest, it probably won't fix the overheating, but it still should be done.

 

It shouldn't be a 7lb cap, it should be around 16-18psi. You don't want lower, it can allow the engine to overheat. Under pressure coolant boils at a higher temperature.

It'll also take care of the vacuum that's collapsing the upper hose. As coolant is heated it expands, as it cools it contracts. The cap is supposed to allow antifreeze from the overflow tank to come back into the system as it cools.

Make sure the tube to the overflow tank isn't blocked as well.

 

Ok, I replaced the rad cap with a 16psi and also replaced the overflow hose and lower radiator hose. After all that I let it run for about 15 min and it started to over heat again.

 

After you shut the engine off, how hot is the lower hose? How hot is the upper? There should be a difference in temp.

When is the last time you flushed the system and changed the antifreeze?

 

I will check the temp tomorrow, but my radiator is 3 weeks old and today is the 2nd time I've changed the fluids since I had to replace the lower hose.

 

When did all this start?

 

About 2 months ago not sure what happened to start it all. I tow all not sure if that had anything to do with it.