I have a '96 Dakota 6-cyl that has started to behave kinda strange. I start it cold, temp gauge comes up to normal and stays stable until about 15-20 minutes down the road and then starts slowly creeping up. Oil level is OK, coolant is OK (no leaks), replaced the water pump in May of last year (with help from the forum, thanks again). I haven't replaced the thermostat, I'm thinking that could be causing the problem or maybe a defective temp sensor. Any troubleshooting suggestions would be appreciated.

 

I would say replace the thermostat first. It is cheep and easy. Next replace the sensor. Just remember for the sensors, there are 2. One with 2 wires for the computer. One with 1 wire for the guage. You should replace the guage. But replacing both is not a bad Idea. It is cheep.

 

Crazy, thanks for your response. I haven't changed out the thermostat yet because it's been too hot to work on it. But I have noticed that when the engine is cold and starting to warm up, the thermostat seems to be working OK. Gauge needle goes up, backs off, up, off, etc. until that point where the needle doesn't fall back and keeps on moving towards high. The guy at Advance suggested my fan clutch might be at fault. If I did my research correctly the fan should spin easily by hand when cold and not so easily when hot. I tried that today with the engine cold and it was stiff, wouldn't even spin a full revolution. Tried it again with the engine hot and same results. Sounds like the clutch might be at fault. Your comments would be appreciated.

 

any luck?

 

Deerkiller, sorry I didn't respond, I had forgotten about my original post.
Turned out the fan clutch had failed. The fan wasn't moving air fast enough to maintain proper temp when the engine heated up. I replaced the clutch assembly and that fixed the problem.

 

thats fine, i was having the same problem around then but my radiator was clogged so poured some HC acid in and cleaned it completely out (with radiator out of truck of course lol) and its good as new now, might put one in, in the future after buying baby stuff lol....really need to win the lottery....gues my numbers are working.....12345678....etc lol

 

how many coolant temp sensors does a 93
3.9 have

 

2 sensors. One 1 wire for the gauge only. One with 2 wire for the computer only.