I have a 98 4.3 V6 4x4.. It runs just fine and the temp gage always stays a little under midpoint when I'm driving. The other day I was sitting in the parking lot waiting for my wife to finish shopping and noticed the temp gage was almost to the red zone. I quickly turned off the truck and waited for her return, as soon as I started the truck it cooled back down to it's normal temp. After it cooled down, I check the fluid level and it was full to the top. Today I stopped on the way home from work at a Mc Donald's drive through and then parked to eat my burger. Again the temp started to rise. I let it go and it just about got into the red zone. I finished eating and got back on the road and the temp immediately went back to the normal range. When I got home I tried to spin the fan blade and it did have some resistance to movement. So it must be working somewhat.
- I sort of ruled out the thermostat as it keeps the temp at the normal level most of the time.
- The radiator isn't leaking and must be doing it's job. But maybe not good enough?
- I have no idea how much restiance the fan should have when hot. Is there a measurement I could make to test that, or should it be locked tight when hot?
Anyone have any suggestions, other then not eating fast food.. LOL
Joel