06 LS Overheating.

[JPShields]

I have a 2006 Lincoln LS, I've owned it for about 4 years now and have loved it and treated like my child. That being said I have put some time and money into keeping it running...still love it though..

... Recently had a problem with overheating (on the interstate w/ no a/c on). Pulled a code P1299 (Indicates an engine overheat condition was detected by the cylinder head temperature (CHT) sensor. An FMEM strategy called Fail-safe Cooling was activated to cool the engine.) Replaced the heater control valve 4-5 months ago. Cooling fan only seems to kick on when a/c is running.. checked relays and all seem to be fine. Could it be the cylinder head temp sensor itself? Any other ideas?

Any help would be greatly appreciated..Thanks

 

[JPShields]

Also....
No fluid loss... I haven't yet tried burping the system... I have a difficult time believing that's the problem only because I haven't fiddled with the system to cause air to be in the lines... The overheating has only happened twice.. And temp gauge seems to stay within normal ranges now...but I haven't driven it long distances or at high speeds since.
Thanks

 

[Robot]

JP, when you have the a/c on, does the temp go down? I had this problem with another car and it turned out to be the temp sensor for the fan itself. Sorry if I am late on this. BTW, be on the lookout for running weight and distribution. I am gonna try and post pics of the scale ticket.