Hey guys this is my first post I have been lurking for a while but couldn't find the answer to my problem. I have an 06 4.7 D with 3.53 pulling a 25ft TT which weighs about 4600lbs loaded. We just did a round trip of 1700 miles and most of the time the temp was 3/4's. When pulling hills the rpms would range from 4-5k depending on speed and hill size. What was weird to me was that the clutch fan would not engage if I was higher then 3800rpms and if I pushed it I think it would have totally overheated. It does have the tow package on it but with highway gears. I plan on swapping out the Tstat but not sure thats going to cure the problem. My folks were behind me pulling a heavy camper around 5500+lbs with an 01 Grand Cherokee running with and without AC and the temps were right at 1/2 the whole time. The jeep has 3.73 in it. An suggestions to this problem. I'm thinking that maybe the radiator is clogged or the Tstat needs to be replaced. The truck is still under warranty and has 44k on it. Thanks in advance for the help.

 

Take it to the dealer and have them look at it. I sounds like the the fan is not engaging maybe you should look at installing an elec. fan.

 

Boondocs:

I am not a towing guru, but 25 feet sounds kinda big for the 4.7 motor even if you are only at 4600 pounds.

In any case, your fan should not engage at speeds over 35-40 mph as it will not do any good. Simply moving down the road at those speeds will move more air through the radiator than the fan ever could.

Since you have an 06, there should not be any clogging issues with the cooling system as the coolant is rated for 5yrs or 100k. If your t stat runs a hare below half at other times, it is probably ok.

BTW, running any engine above 4k for an extended period of time like that is quite hard on it, and may possibly self destruct it.

Another D owner with a Hemi was towing with a good sized load through the mountains, and he was running it at or above 5 k quite abit. The engine did not survive.

IIRC, the engine had 50 or 60k on it, and Dodge denied coverage under the PT warranty saying he had abused it.

Don

 

I think n8ech is correct about not to exceed above 4k range RPM for long period of time.
I have 04 Hemi Limited with tow package and towing 6.5k loaded 18' enclosed trailer. When going uphill I believe 6% grade if I try to keep up with traffic saying 50-55MPH for about 5 minutes I see the temp gauge raised above half by that time the RPM was above 4k so I slowed down to 35-40MPH and the RPM below 4k and see the temp gauge dropped. With that experience I alway try not to go above 4k RPM. In your case you should have dealer look at your D.