Overheating???

[michaelyoung254]

I have a 1995 F-350 Crew Cab with a 5 speed manual tranny. While pulling my 29' Fifth Wheel trailer (between 65 & 70 mph) it seems to be getting pretty warm, especially up a slight grade. At least that is what the factory gauge is telling me. Normally unloaded, the gauge runs almost dead center in the gauge, but when pulling the trailer as described, it get VERY close to the HOT mark. If I slow down to about 60mph, it cools down a little, but not to the point where it runs unloaded. It's not boiling over or loosing coolant. I'm going to put in a mechanical gauge to verify the temperature, but I'm not really sure what the normal operating temperature should be (forgive me, but while I've been working on gasoline engines since I've been big enough to pick up a wrench, this is my first diesel, and I really don't know much about them) What is the temperature range for a 7.3 powerstroke, and at what temperature should I start getting concerned?

If it is running hot, what could be causing this (it has a relatively new water pump, radiator, and belt)???

[mattymx]

The factory stat is a 195. There is also a replacement that is a 203. Diesels need heat to run and will actually run better with the 203 installed. This extra heat helps the combustion process and actually increases performance a bit. A true mechanical gauge will help out to tell exactly how hot your PSD is running. My bet is the stock gauge off a bit, but you never know until you get real numbers to go by. You mentioned that the pump and stuff is new. Make sure you have the correct coolant. I run fleetrite that I get from International and I use the precharged coolant. If I were you, I would get some of that coolant and do a change. That way you will know you have the correct coolant as it is vital for the engine blocks life.
Welcome to SoCAPS!!!

[mschn99]

Running close to the top of normal isnt quite right though. I would definatley be looking at both the T-stat and possible the fan clutch. Diesels dont generate as much engine heat as gassers if your looking at what actually gets transfered to the coolant, thats why they take so long to warm up in the winter without a block heater in cooler climates. You almost dont even need that fan clutch if you are moving in one with no load. Since yours only does it loaded, i would definately be looking to see if the fan cluch is free and if it is not locked up when it is warm....

[n.novelich]

Mine did the same thing and every one said the temp sender was bad. Found out the overflow container had a seperated at the seam.