I have a Lexus LS460 with 132,000 miles. When I first got it, the temperature gauge started to run a little above normal so I took it back to the used car dealer and they found a bad thermostat and they replaced it. A month later when not moving the temperature gauge would rise but go back to normal when moving at highway speed. I took it back and they replaced the module for the cooling fans. Problem was then solved. Several months later, the heater started not working as well, so I replaced the water pump, when replacing the water pump, I accidentally bumped the coolant overflow hose on the radiator and the radiator plastic just crumbled. I replaced the radiator. Then the heater started working like it should. Now today (about 2 months later) the temperature guage went up to 3/4 of the way up and then it immediately went back to normal and stayed in the normal range. Is this just an electrical gremlin or should I be worried?
Which model year?
2010
I would keep an eye on it, but I would not let it keep me up at night either. I had an LS460 and I can tell you there are a lot of sensors in that car. You may be seeing a gremlin. If it continues to happen consistently, you may consider further action. While I applaud your attentiveness to your car instead of your PHONE like most drivers, I would hold off on panicking for sure, or even much concern, until you can verify it is a consistent problem. Even then, don't panic. It could just be a sensor going out or an electrical short.
Sticking thermostat?
