After a much-needed vacation, I am back and ready to figure this thing out. For those of you who are unfamiliar with my trouble, or have forgotten, you can look HERE.

Before going away, I purchased an ECT sensor but I haven't changed it yet. I changed the oil Friday evening, and I wanted to see how just changing the oil would affect the problem. We went on a 36-mile sprint down the Interstate Saturday evening and I watched the water temp guage closely. I set the cruise on 74 and kept it there for the whole trip. The guage stayed put for a long time, but after about 28-30 miles, it stated creeping up. Most of the time, the guage stays at about 1/3 of the normal range. At first, it went up to about 5/6 of normal. Then it did something I hadn't seen it do during this trouble. It actually fell back down a little, to about 4/5 of the normal range. It set there for a while, then it started up again, to almost the top of the normal range. Then it fell back again, to about 5/6. It has not done that kind of fluctuation while I have been monitioring this problem I have been having. Right about when time came for us to exit the Interstate, the guage was almost at the top of the normal range and as soon as we got onto the other road, it came right back down to where it normally runs. A key thing is that it never did actually get up into the H area on the guage. Maybe it would have gone higher with a longer trip. Another factor was the outside temp, which was pretty cool, but later on when we retuned home, the truck behaved in identical fashion when the temps were even lower. I'd say it was in the mid to lower 60s. I believe that changing the oil helped me in some way, but the problem didn't go away, so I still need to resolve the issue. I am on the verge of purchasing a travel trailer, and there is no way I can take off down the road pulling a 7700# trailer until I figure this out.

I guess my next move would be to change out the sensor and see it that helps. Hopefully I will have time to do it before my son's football practice on Monday evening. I am beginning to consider that thermostat more, but not sure what to do next.........

 

My friends Dodge was heating up like you are explaining and when I checked his radiater it was full off road grime and bugs. There was almost no sign of grime on the outside trans cooler, a.c. condencer, or the inter-cooler but in between the inter-cooler and the radiater was about an 1/8 inch of crud, so I would recomend back flushing your radiator as that was the only thing wrong with his.

 

For a long time it's been a widely held belief that the temp gauge on these things is nothing more than an idiot light with a needle.

If that is the case, I would be more inclined to think that you have a sensor problem more so than an actual temperature problem.

 

Do you hear the fan clutch engage when it runs hot? If nothing else, it might indicate whether or not an overheating problem exists. I just got done reading the original thread and have a couple of questions. When did the problem start in relationship to the radiator hose bursting and does the radiator cap hold pressure? It sounds like a coolant circulation problem ie: water pump, radiator or radiator hose sucking shut. As mentioned by someone else, check for debris in the front of the a/c condenser and radiator reducing air flow .

 

The hose blew off way over a year ago. It was about 2 or 3 days after I got the truck and I almost had a heart attack. I first noticed the overheating problem about a month ago. I did not have time to look at anything this evening, so I will have to try and look at it tomorrow. I have that new sensor and I just need to make time to put it on. I have definitely added debris in the radiator as something to look for, and radiator hoses and cap as potential items to replace. THANKS.........

 

You said the hose blew off, did it over heat? Or did you stop the truck in time before any damage accured? Maybe you have a blownhead gasket. Now that I think about it, why did the hose blow off in the first place....was it just a loose hose clamp (hoses dont just blow off for no reason)? Maybe it had a blown head gasket when you got it, and now it has just gotten worse.

 

If water temp was an idiotlite, like oil preasure, I dont think it would rise and fall but would peg solidly at mid range.
If you have a loose ground that could explain what you are observing.

 

No, no....there is no blown head gasket. The hose clamp failed is the only reason the hose popped off. It was that confounded factory clamp. I replaced all those factory clamps with the screw kind when I put the new coolant in the truck. I have driven the truck about 20,000 miles since that happened. The overheating trouble just recently began happening.

Where could such a loose ground be? In the wiring for the guage? Tell me more, please!

Although I didn't have time to mess with it any this evening, I do have a little more info. I found out how towing a 7700# camper affects the overheating problem. In about 5 miles, or a little less, she was right at the bottom of the "H" range. I was tooling right along, in OD, doing abiout 50 mph on a secondary road when I looked down and noticed the guage. Also remember, I had left the SC tuner set at high perf because I knew this would be a short trip. It sure didn't take long for her to heat up with that load hanging off the back end.........

 

i am kinda betting on what 95psd said. before i bought my psd i owned a chev gasser. and one day i had temperature problems, and i chenged thermostats, oil, you name it and all it was, was a matter of taking the garden hose and spraying out the radiator fins. you wouldnt believe the crap that came out of there. it solved my problem, and it never happened again. just thought i would tell you my story.

 

Does it overheat without the tuner?

 

Hmmmm....I dunno, slc10844....I have never driven it for long without the tuner turned on.........

 

Worth a try. Put the stock program back, hook up the trailer and go for a spin.

 

Most gauges are really amp meters that measure the current flowing thru the appropriate sensor. Since current is a direct function of voltage and resistance (I=E/R ohms law) and a bad ground increases resistance it affacts the way the gauge reads. An intermittent bad ground will give you a variable presentation. It could occur almost any where including internal to the guage. Often it is nothing more than a little corosion at a connection or it could be a very slightly loose mounting screw ya just gotta trace it out.

Another thing 50 MPH in OD on my rig is somewhere around 1000 RPM, dont know for sure cause I never never do that. It is way to low on the torque and power curves and is garenteed to make you run hot. try to keep your RPM up around 2000 especially when towing.

 

I noticed on my 97 that when I would get in the truck in the morning, the temp gauge would be 1/4 way up before cranking. If I tap on the gauge it will fall to where I would expect it to be. It could not hurt to get another water temp gauge to verify the factory gauge. I have little faith in the factory gauges.

 

Phydeaux88, I actually didn't realize I was wound all the way out to OD until I just happened to think of pressing the OD lock-out button and I felt the truck downshift. It is amazing to me that the truck will never downshift on it's own until it lugs down pretty darn slow. I guess the tuner contributes to that condition. I wouldn't normally tow like that, but you have to understand that all I was doing was towing the trailer from the guy's house I bought it from to my house. This was a trip of about 7 or 8 miles. I was on the secondary road because I didn't have any lights (or trailer brakes) hooked up, and there was no license tag on the trailer yet either. And besides, I am not used to towing anything anywhere near this big, so I was pretty distracted by watching carefully to make sure I didn't knock down anything on the side of the road.........