Hi, yesterday my 4.7 Durango overheated after driving for a while. However, when i got onto the highway the temp dropped back to normal. I also revved the engine during long red lights to maintain normal temp...Today i checked the truck over, the coolant level is good, although i have green in the system and not red/long life coolant...... there is slight play when i wiggle the clutch fan back and forth.... I then Ran the truck at idle... the electronic radiator fan did kick in but took over 35 minutes WITH the AC on. I guess thats normal, it was 50 degrees out today. Also, i noticed the heat took a long time to come on, even with the engine hot.
The truck did not overheat in the 35 minutes or so i had it running. weird. intermittent overheat? Im leaning towards a weak water pump and or faulty fan clutch.

 

This may not pertain to dodges...but I had a bronco that did the same thing(96 with a 5.8 liter) and I could not figure it out. Changed the thermostat and clutch fan and just about everything but the heatercore and never figured it out. Your best bet is to start with the cheap fixes and go from there maybe someone with more 4.7 knowledge can help point you in a betterdirection

 

Check the fan clutch, there is a link to a video on how to do this in the DIY thread. Also the electric fan should kick on with the a/c no matter what iirc.

 

most likely your clutch fan is the problem, however if the water pump pulley wiggles then the water pump bearing is also going out.

now i would also venture a guess that something screwy is going on with your electric fan because whenever the A/C is on it should run

 

I don't have my clutch fan and I have never over heated in stop and go traffic. Even on 110 degree days. But if my gauge starts to climb then i just turn on the defrost or something b/c that will kick on the electric fan.

 

+1. Fan should be on could be something wrong with the fan clutch. E-fans could be a bad motor or bad connection.

 

I watched the video showing you how to test the fan clutch. One think i could not understand, do you test it while the engine is hot or cold? fan clutch engaged or not?

i tried it with the engine cold, my fan clutch felt like it was engaged.

 

Well if you tested it while it was hot, it wouldn't be engaged thus meaning the test would be worthless.

 

The fan spun less than 1/5. Id say from 12 o clock, it only got to 1:30.
I have been busy so i havent have time to look at it. But i want to fix the electric fan first. It does not come on with the a.c.

 

The electric fan comes on when the compressor engages.....not immediately with the a/c switch. If it is cold out the compressor might not cycle on, also is you are low on freon that will keep the compressor from coming on, and won't signal the electric fan to come on. By itself the engine temp has to get to around 220 before the electric will come on to "assist" the mechanical (clutch) fan.
We had a 02 Durango in the shop today, the fan clutch was so bad that while it was running the fan was spinning so slow I could just touch the fan and stop it! It had a lot of slop in it also.