2004 3.7L with a bit over 60,000 miles. I've never had a problem with it overheating, and haven't changed the coolant yet (I think the owners manual said 100k?). I haul with it quite regularly, and will often pull a small car, our camper, etc. Again, never a problem.

My father in law used it to tow an S10 on a tow dolly for about 45 miles last week. He said the check gauges light came on and the temp sensor went about 3/4 of the way up (normally half way, of course). It's normal now again, and was fine by time he dropped off the truck and got it back to my house.

We're going on a long trip with the camper for vacation soon. What's my best plan of attack for troubleshooting this? Should I just change the coolant? Replace the thermostat? Something to check on the water pump (or just replace it)? Or should I not really worry about it with the recent heat wave, since it was like 90+ when he towed with it.

Thanks guys.

 

Coolant is rated 3yr/50kmi, it's Not the 100k stuff. The 4.7L's are Notorious for overheating and cracking/warping heads. I would not wait. Flush your coolant system and replace your radiator. Guys have had nothing but problems with the radiators clogging/corroding internally and blocking flow.
Spend the $2-300 now and save yourself new heads/gaskets...$3k total.

Most definately flush and put new coolant in! I'd go all the way with a new radiator as it's 8yrs old now. Do a search and you'll see.

 

Thanks for the info dirtydog - but just to make sure, I do have the 3.7, not the 4.7. Does the rampant overheating & cracked heads apply to the 3.7 too?

 

Not so much on the 3.7. The early 3rd gen (02-04) seemed to have some cooling issues with the radiators partially clogging up and causing overheat issues. The design of the 4.7L he mentioned is weak in the overheat area and usually blow a head gasket when overheated.
I am surprised that the check gauges light came on at only 3/4 on the temp gauge since this is still considered the normal range.
I would get it up to normal operating temp (thermostat opened) and turn it off. Feel around the radiator fins for cool spots, especially at the bottom. This is a sign of a clogging radiator.
I would go ahead and have the system flushed if there are no cool spots and see what happens.

 

My bad. Thought I seen 4.7L. Do the 3.7's have clutch fans? maybe that is the problem?