Bad Thermostat or Fan Clutch

[dansilva929]

For the past month my temperature gauge has been acting strange. Most of the time the needle is slightly to the left of the center of the gauge. Every now and then the needle shoots all the way to the right into the red zone. It's done this a couple of times in the morning when the car has been parked all night, so the engine can't possibly be overheated. I suspected my thermostat had gone bad. I then asked my father about this. He told me he had a similar problem with his old Explorer. He changed the thermostat, but he continued to have the same problem. He then changed the Fan clutch and problem solved. Has anyone on this board dealt with this issue? If so, how did you resolve the problem?

 

[kkdoughboy]

Does this happen once the car is warmed up and your driving it around or just when its started up?

 

[ARTTII]

Still under warrenty? I would call your dealer asap to get the problem documented.

 

[dansilva929]

Does this happen once the car is warmed up and your driving it around or just when its started up?

Mostly when the car has been started and allowed to warm up for a while.

 

[ski]

Check the coolant level in the reservoir, and refill it if necessary.

If it's ok and the problem happens in all types of driving conditions(idling, stop and go, highway speeds), then check the coolant temperature with a thermometer when it happens.
If it exceeds 230 F, then either the thermostat or water pump is failing, the radiator is blocking up, or the radiator hose that feeds the coolant into the engine block/water pump is collapsing.
If it's between 180-225 F, then either the signal to the coolant temperature gauge is erratic, or the coolant temperature gauge or the coolant temperature sensor is failing.

If the problem happens only during idling and stop and go driving, but does not happen at highway speeds, then the cooling fans may not be working. BTW, they're electric, and do not have a clutch. Sometimes they fail to run because a fuse has blown. Check to see if they're running the next time it happens.