Hi all,

Have a 2002 Excursion 7.3L with about 89K on it. Live in Richmond, VA and yesterday it was mid to upper 90s and I noticed the temperature gauge creeping up. Normally it stays at the halfway point on the gauge. I was driving a little aggressively (not wild, as my wife and 2 newborns were in the truck - just accelerating quickly) and I watched the needle go up to about 1/4" from the red zone. AC was cranking full blast at the coldest setting. Never got into the red, but stayed up there. I slowed down and it fell a little, but never got back to the standard half way mark. I do have a DP Tuner and had it on 80 economy setting.

Now a little history on the truck - little that I know - Sarasota, FL truck - previous owner had some heating issues. Vehicle was owned by the wife of a trailer company owner. Sometimes it was used to move empty trailers (from car trailers to larger enclosed trailers) and it the temp would rise. She had the radiator replaced, flushed ,etc. (at least what she told me over the phone). She said it never got into the red - always pulled over wWhen I drove it back from Orlando last October it did this one time before. Turned off the AC and slowed down and it eventually settled down after about 5-8 minutes. That was interstate driving.

This time was around town and I arrived at my destination before I could see if it would calm back down after I turned the AC off. (Wife would not have agreed with no AC for too long anyway). When I did get to my destination, I let it idle for about 8 minutes before turning off and temp gauge fell a little, but never got back to the standard half way mark.

Sticky thermostat? I assume that was replaced with the flushing/radiator replacement. Any thoughts anyone?

Weird - but I had to give my wife the truck today and am sitting at work thinking about it....

Thanks
Joe

 

Can you hear the fan clutch engaging to pull more air when the temp rises? In the summer with the a/c on, I can hear mine for a short time when taking off after an idle.

 

I doubt I would be able to hear it - my truck is so damn loud - previous owner put a big honkin' exhaust on it. You can hear me a half mile away!

But I will listen for it - can I check it stationary?

 

That gauge on the dash is a glorified idiot light. I would seriously look into getting a real water temp gauge for a truck that is seemingly overheating to rule out if the dash gauge was bad anyway and to be much more accurate chasing down an overheating issue. Just my $.02

 

Good point, Jason. I was just mentioning the fan clutch as an indicator that if the temp was rising, the extra heat should be causing the fan clutch to pull harder, if in deed it is getting hotter. The fan clutch could also be slipping and creating the problem, too.

 

Good point. I am thinking about getting an Aeroforce gauge anyway.....

 

One way to check the fan is to start the truck and don't let it warm up, start driving it but take it easy. At about 20mph you should hear the fan roaring, even over the motor.
The other thing to check is that you don't have a bird's nest stuck in your radiator. Last person that found his birds nest didn't see it tell the radiator was pulled.

 

When we were trying to find Bergerson's overheating problem, his stock temp. gauge would read normal while the coolant was boiling! It also seemed to lag the temperature rise.

Another vote for an aftermarket gauge.

 

The cooling system on these engines is built as overkill. If that temp gauge rises at all from the midpoint (and assuming the gauge is working properly), then you probably have a sticking thermostat or a failing water pump.

Your specific symptoms of higher engine temps on the highway (and getting on it a bit to increase the engine load) lead me to vote for a failing water pump.

 

Are you seeing any physical signs that it is actually overheating other than the gauge rising?

 

No - but what should I be looking for?

 

This thread has some good information...

https://www.ford-trucks.com/forums/9...ing-issue.html

 

Thanks for the thread info.

So this weekend I went to Wintergrreen ski/golf resort - About 45 minutes southwest of Charlottesville VA. She rode fine all the way out there, cruising about 75mph. Then we got to the bottom of the mountain and started heading up - 15%+ grade. Had to stop twice as the temp gauge went to just shy of the red zone. Cranked the heat, popped the hood and let it idle at the side of the road. After about 5 minutes the temp came back down to the midway point. This was Friday night. Saturday - drove down the mountain - played golf and the same thing happened as we went back up the mountain. Obviously, under any load, the Ex gets hot.

Also, when it did get to just shy of the red zone, the "check gauge" light came on. Is that normal for when the temp soars?

I am wondering what to chase first - water pump or radiator - I doubt it is the thermostat.... any more thoughts from anyone?

 

I doubt a thermostat as well, but coupled with something else it could be a problem. Did you take it out and throw it in a pot of boiling water and monitor what temp it opens? I had a thermostat that wouldn't open....

Have you taken your radiator out and looked at it? Made sure it isn't plugged up?

 

I had a Z28 that used to do that. It was a plugged radiator. I am leaning towards radiator or water pump the more information we get on this one.