About four months ago, my 2001 XJ's temperature sensor pegged hot and the "Check Gauges" light came on. As I started to pull to the side of the road, the temperature went back to normal. In the next few months, this happened two or three more times. Since then, the gauge has been behaving normally. However, now the Jeep is having trouble starting. When I try to start it, it cranks for several seconds and usually doesn't start, but when I immediately try to start it again it starts right up. It seems like the battery may be starting to go, but I would think if the battery is the issue, the Jeep wouldn't start right up the second time I try it?

I'm planning on replacing the temperature sensor. From what I've read, in a 2001 XJ, the temperature sensor controls the gauge and sends the temperature to the engine. There's no separate temperature sending unit. Do I have that correct?

What steps should I take to diagnose the problem with starting the Jeep? Is it simply a problem with the battery?
Could the difficulty starting be related to the problem with the temperature sensor?

 

Your temperature could be anything from a faulty temp sending unit to a sticking thermostat or restricted coolant flow through your system. You should diagnose your trouble there a little more in depth to save your head/head gasket.
As for your non-start issue, you have not given enough information. I do not believe the 2 to be related (yet).

Todd

 

temp will effect fuel scheduling..mixture. when cold the computer enriches fuel mix and when warm it cuts back on fuel . Is your starting trouble all the time or only in morning when actually cold or when actually warm after driving. or both. With that said....it could be a bad fuel check valve-bad fuel pump-bad coil rail unit.....the list is endless

 

Check the wires to the temp sensor in the thermostat housing. Usually when the temp sensor dies it stays dead, but I have seen the wires to the sensor pulled tight and frayed.

 

Thank you for your responses.

I'll check the wires to the temp sensor.

The starting trouble is all the time, both the first start of the day and after driving.

 

Since you only have 1 temp sensor that feeds gauge and computer...if the gauge reads cool/cold when cool or cold...and if it reads normal operating temps when warm....the temp sender is not your issue