Hello, I have been reading a lot of the posts here on the over heating problems on the 4.7 engine.
I currently own a 2002 durango with the 4.7 approx 120,000 kilometers on the engine.. I have had the T stat changed and coolant flushed and a new rad cap when the engine overheated coming back from a trip.
But now that i am actually paying attention to the temp gauge I am not sure if what I am seeing is normal movement or the engine running hotter than it should.
Gauge will read for the most part just below the half way mark, then sometimes will go all the way to the 3/4 mark. The electric fan is running, the clutch fan is running and this extra movement will mostly happen at low speed in town driving. If I put the tranny in neutral and rev the engine around 1500 rpm you will see the temp gauge drop after a minute or two.Is this normal or am i being parnoid/ I do not want to get into really expensive repair bill if i over heat the motor.
Thanks

 

Sounds like the radiator is pluged with debree's. Take it to a car wash open the hood and spray out the condenser and the radiator fins.

Why did it overheat in the first place?

 

I would also look at the fan clutch being the culprit. It sounds like it may be shot. I did however have a t-stat that was stuck partially open that produced nearly the same symptoms. Revving the engine would put enough pressure on it to push the coolant past the t-stat fast enough to cool the engine but idling and slow speeds sisn't produce enough pressure. Did you use an OEM or quality aftermarket (like Jet) t-stat or an autozone POS? I've had t-stat's fail within a few weeks of replacement.

 

The first overheating issues was because the Tstat failed, I had the delaership change it and flush the coolant. This is the second time for a coolant flush in 4 yrs. I will try cleaning the condesner and radiator fins. It is possible the T stat has failed again. It has happend to me before to.How can i tell if the fan clutch is no good? Will the fan turn freely? Thanks for the feed back.

 

It is pretty easy to turn freely and is a fairly common problem.

 

So the engine has 0 miles? Awesome!

 

While cold turn the fan and see if there is some resistance. If none then the cluch is bad.

Also do you hear it engage when it gets hot?

 

+2 on that
+2 on that A covered or clogged radiator will cause this problem.
In personal opinion you should change to a 180 degree T stat. that will automatically drop temps under the hood. just that alone will drop temps half the way between the middle mark and free up a little horse power.
Your fan clutch is probably gone that is why when you stop you get those high temps it is time to to place it. I did a thread called What water pump check it out for a solution to getting the fan clutch off.