Land Rover Repair: /overheating., engine cooling system, calcium buildup

Question
On Christmas Eve I notice my temp gauge rising to hot and the red light on. Then a few minutes it went back to normal. Later I added water and drove 150 miles round trip with no problem and the gauge reading normal. Now after 4 day of adding the water the gauge will erotically go to hot with the red light on and stay for several minutes then gradually go to normal and return back to hot.. I have a 1998 Range Rover 4.6 HSE. Thanks.

Answer
Hi CJ,

wow...your message sure is, er, exciting.  An erotically hot Rangie engine attracted to red lights...at least its not moist. *

Enough foreplay...

this sounds like either a temperature sensor or thermostat problem.  Usually, the thermostat behaves this way just before it fails.  If its been awhile since you replaced the thermostat (if ever) that's where I'd start.

Other possible causes could be calcium buildup in the radiator, air blockages, hose leaks.  Have both the radiator and the engine cooling system pressure tested for leaks.

Best of luck,

JohnMc

NB: amazing what one little typo can do to a sentence. :)