New post here. I bought a used 1998 Cherokee Classic 6cyl 4WD recently and have noticed a annoying problem. When the temp gauage gets to 1 "hash mark" before 210 (top center) the truck seems to want to stall. I "chugges" a bit and as soon as it hits 210, it pops back to normal.
No warning lights, etc. have come on, ever. My mechanic can't figure it out without costly trial and error, so he's suggested a "wait & see".
Any ideas? Anyone encounter this too??

Thanks

 

What has he tested so far? What has he replaced? What were his Ideas?

 

he has done a full tune up, replaced wires, cap etc also replaced the fuel pump in the tank.
Some people suggested it may be:
1) a ground problem from the thermostat or hot wire
2) O2 sensor at the engine

It is more annoying now than a problem but I'd like to get it squared away

 

Might be a good time to do a full coolant flush and replace the thermostat. I don't have electrical wires to my thermostat so I can't talk intelligently about that. Sorry

 

I would lean towards the number 1 o2 sensor failing. That's right about the temperature where the computer switches modes, and if the sensor is lying to the computer, it may temporarily be flooding the engine, or starving it of fuel.

If you've got somebody who's got a scanner that can do digital readouts, namely o2 sensor readings, go for a drive with the scanner hooked up and have the passenger watch the readings. It will be quite obvious if that sensor is on it's way out when you get to that temperature.

 

im just throwing this out there but on the h.o. 4.0 is there still the coolant sensor in the side of the block could that possibly be going out on him and sending goofy info to the computer?

 

I have a problem with mine, its cutting out power in the low range right after its first started and if i hold the throttle in place when it does, it makes a popping noise "detonation ?" in the engine. I have replaced the TPS, IAC and the MAP sensor with no codes thrown and still doing it after 2 years.
Just recently got a check engine but its for the tranny shiftlinkage not setting up correctly for the engine start.