Overheating on long interstate runs

About a month ago my 3.4 5 speed randomly runs hotter than normal goes 3/4 up on the cluster. Pressure tested found coolant leak from water pump. Replace pump and timing belt. Drive the truck a week around town seems fine. Head back out to local kayak shop about 30 min away up the interstate same exact place temp gauge creeps up again. I went back replace thermostat the old one didn't have the jiggle valve, install a new Stat with the valve at 6 o'clock position. I hook my scanner up at highway driving seem to run at 210-215* the temp gauge still sits in the middle. One thing I did notice I cut the heat on high it will suck about 15* of heat out of it. Kind of torn between a fan or radiator issue since it's dropping so much temp off. Or at 250k it might be due for a set of headgaskets

 

Take a really good look at the radiator area BEHIND or INFRONT the AC condenser,

This is an area where the radiator gets plugged up with dirt because the condenser is sweating on to
the radiator and plugs that section of the radiator up with dirt.

You might have to just spend 100 and get a new radiator,

If you run the engine hot you will get in the danger area of a head gasket

 

If it overheats on the freeway, it's unlikely to be a fan issue.

You could try @Timmah! 's video for a cheap and easy cleaning procedure that might help:

 

I ordered a radiator for $100 today gonna see how it does after that

 

Consider new hoses while you’re in there, coolant flush, and burp the Heck out of it.

 

You could but in a lower stat in there too

 

I got a 170 from o'reallys

 

I would get the 170 corolla stat from the dealership,

Mine failed from advanced auto 3 months later,

The Toyota one is so much better in quality

 

What’s the front of your condenser look like? If it’s all beat up from rocks and road trash it’ll cause your radiator to heat up. Also occasionally hosing out any dirt from the backside will make a big difference in hot weather. When I spent a lot of time on dirt roads I had to do that pretty often. It would significantly drop the highway temperature readings.
Just be careful of the fins when cleaning out the radiator or condenser. You can use air too but I hesitate to recommend it as it is really easy to flatten all the fins and ruin the radiator or ac condenser. Use low pressure and keep some distance. You may find some parts like the grille and shroud need to be removed to get access for a thorough job.

 

a picture is worth a 1000 words... I have a post called "Radiator basics", this is exactly what you are experiencing.

 

Tell me about it... A few years ago I spent the better part of 1.5 hours straightening out the fins after I hosed off the radiator.

 

Radiator fixed it. Put it in at work gave her a hard 70mph home and stay 192-194

 

Xlnt