95 F150, manual, 2wd, 130,000 miles

Anybody run into this before? Usually I can run 80mph with the ac on high and my factory temp gauge never comes off of the "N" in NORMAL. Now at 80mph with the ac off, the gauge reads at the "R" or "M" of NORMAL. Around town in stop and go traffic it is at "L" or higher. I drove 5 hours straight two days ago. It has not completely overheated and boiled over..... yet. Heres what I've tried so far. I flushed the coolant system since the fluid was a little brown and chunky. Checked radiator for mud and debris. Thermostat is fairly new (my fourth one). Radiator is also fairly new due to a run in with a cavalier. Doesn't use coolant, so probably not head gasket, especially at that low of miles. Checked fan clutch, seems to be working properly. Could it be the water pump? Maybe time for another thermostat (havn't had good luck with them in the past)?
The AC goes out totaly (blows warm air) when I come to a stop, but works fine when I am moving. Let me know what ya'll think. THANKS!

 

Do you have a fan shroud or was it lost in the accident?

 

everything has been replaced that was damaged. the reck was over a year ago.

 

If you replace t stat use a fail safe if it ever fails it will stay open not closed like most.I drill a 1/8 hole off to one side on t stat they operate smoother & last longer.

 

You are not moving enough air at lower speeds that is why you are heating up and the air conditioner is not working. This is usually a fan problem I would revisit the fan. Was it replaced after the wreck? The bottom line is you are not getting any air flow at low speeds. I have driven cars/trucks with out fans before (all belts and pulleys where in place.) if you stay above 35 mph you are fine below that and they get hot.

 

I've been trying to get back online for a while now. Guess the site was down. Anyway, I replaced the fan clutch and it still runs hot. I also replaced the the temperature gauge sensor (one on back of block above starter). When I took out the old sensor I let the coolant drain completely and I ran water through the radiator for about 10 mins to flush it as well. I'm still running hot guys! Its drivable, but I don't know for how long. I guess I'm gonna try the thermostat next. I'll move on to the water pump after that, but I hope I don't have to.

 

Check the wiring to the temp sensor. If there's any degradation in the wiring insulation or a dirty contact, the poor connection between gauge and sensor can give intermittent false readings. Changes in the supply voltage to the gauge can also make them jump 'round a bit. If your alternator isn't charging fully at low RPM, or there's a heavy draw [AC blower on full blast, lights, etc] then the voltage drop will make the gauges fluxuate. Even with corrected wiring, my temp and oil pressure gauges vary depending on system voltage.

 

I recently replaced the radiator in my truck. Made a night and day differance. When was the last time the radiator was washed (outside). Could be plugged up.

 

radiator is fairly new, and the outside is clear of debris. I have flushed it twice as well. I plan on replacing the thermostat tomorrow, and move on to the water pump if need be.

 

Thermostat fixed the problem. Go figure! I've put numerous thermostats in it (4 or5), and they only seem to last 1-2 years each. I've used the cheap ones, and the expensive ones, it doesn't seem to matter.

 

You can add redline water wetter to you coolent that makes a huge diffrence and it realy works. And yeah thermostats are made in china and are poor quality go figure the drill tip above is safe insurence but it does cause you truck to warm up slower which sucks if you live where it's cold.

 

Here is something I just ran into last week. What ratio of water to antifreeze are you running? I had straight Antifreeze and my 300 6 cyl was running to the top of the gauge I did some research and found that is a bad Idea antifreeze does not disipate the heat as fast as water does also strange as it sounds straight Antifreeze freezes a 9 above 0 I changed mine to a 50\50 mix and problem solved.

 

my ratio is 50/50, I though about that too. but the problem is fixed now. was the thermostat. thanks!

 

Just a curiousity question, but in a response above, it was mentioned that it was not getting enough air flow at low RPMs. Maybe switching to a different fan that pulls more air would in order. IMO.