Hi,

Hope someone can help me out here...

I just replaced the thermostat on my Durango SLT 4.7L (2005). this, because the temperature gauge was going up for no reason and then return back to normal. I believed the problem was the thermostat. After replacing the part, I let the engine running for about 15 min with the A/C on and the temp gauge remained exactly at the middle.

Then I decided to move the D and the temp gauge started to raise again. I noticed that the electric fan suddenly went into a faster rpm at that moment also.

Everything else still original equipment.

What could be the problem?

Thanks!

 

Do you have a service manual? They are online in certain places for free if you Google search. There is a section on trouble shooting cooling. Check the coolant level by the overflow tank, not the radiator cap. Does it have enough? Is the radiator cap bad? It could be a bunch of other things like a slipping belt, bad water pump, etc. I'd start with the basics.

 

Are you getting the coolant light or the check engine light? Did you take it to get the codes if any, read for free at Autozone or the like?

 

Hi Sarguy01,

Thanks for responding! I don't have the Service Manual. Will check around to see if I find a copy to download. How do I know if I have a bad radiator cap? I replaced the thermostat and check the fan clutch (which feels pretty tight with no play). The belts and the water pump are originals. I'm getting the coolant light when the temp goes pretty high but that was before I replaced the thermostat. Today, the gauge keep moving the max reading was about 2mm over the middle. I haven't take it for a code reading. I will work on your suggestions tomorrow and post back the results. Thanks again!

Erwin

 

I would change the coolant if it is two years old.
FF

 

Well... I took it to the Dealer and the result was a bent cylinder head. They will replace it under warranty (I still had a few miles available on my extended warranty). It is a strange thing as it never got fully hot or the engine shut down automatically. I was able to run over 20 miles to the Dealer with the temp gauge in the middle (never got hot). It moved around but just a few mm over the middle mark.

The problem is the weeks that this will take.... :-(

 

Well, at least you know and it is covered.