- Location
- Roanoke VA
CTS is new.I would not try the stop leak hack job repair.
As far as the talk about air pockets, if the coolant system is underfilled, you can overheat the engine and the dash gauge will not show it.
A properly working XJ coolant system is adequate to drive across the desert in California or Arizona in the daytime, 100F+ ambient, with the A/C, on long uphill grades on I-8/ I-17. I don't drive those roads every day but I have done it repeatedly in my 2001.
Over time engine components get old and lose their performance and then the coolant system loses its ability in extreme temperatures. Fan clutches get weak, radiators/condensers get clogged with dust and leaves, catalytic converters don't flow as freely, thermostats may not open properly, ...
I would look at the misfire code as well. A weak head gasket can cause some funny problems.
And consider testing the coolant sensor through its entire operating range or replacing it.
Missfire code is fixed, bad coil.