I have a 2003 XKR with 75000 miles. Recently on longer trips the temp gauge peaks out, restricted performance indicator comes on as well as the check engine light. The engine is not hot. Shut the car down for 30 seconds and restart and all is well...except the check engine light will stay on. BTW the check engine light seems to be sensitive to low octane fuel...although I've never burned anything but premium. Now and then the restricted performance comes on for no apparent reason but only lasts for a few minutes. My old xk8 did the same thing . Any ideas what might be causing this? Weak battery was one suggestion but no indication that may be true.

 

need to pull codes for that check light. It will tell you what may be going on.

 

as for battery, just because it starts the car it still may be weak enough to start "gremlins" popping up. That said this one does not seem to be a battery issue.

 

brgjag is correct, we need the codes for this one. The temp gauge issue is a strange one if the engine truly isn't hot.

 

I have a suggestion that will satisfy both issues . . . if you have an Android phone.

The free TORQUE app and a $10 OBDII data port to blue tooth converter will not only read your codes but will display the temperature that the ECM thinks it is seeing.

 

I was just going to post this info. Get the ELM blue tooth adapter, seems to be the most reliable one for this app/droid phone.