I have a 2016 Lexus IS200t with 100,000 miles. In the last few months, there are times we will be driving slightly uphill on a windy road with a sharp right corner turn and the temperature gauge spikes all the way up and the car gives us a warning message about engine temperature. After a few seconds it will go back down to normal! It’s very odd. I’m guessing it’s a sensor issue? Anyone have any thoughts? Doesn’t matter if it’s hot or cold outside - and it always happens in the same places!
Is the coolant full? If so, try replacing the radiator cap. If you have been adding coolant b/c it was low for unexplained reasons, have the cooling system pressure tested.
We checked the coolant and it was fine! It just happens under those circumstances of uphill right corners on windy roads!
there should be a code stored. go to a auto parts and they will scan your car for free and tell you what the code number is and probably the meaning. if you post the code here we may be able to help you more.
Did you check both reservoirs? There are two coolant reservoirs, the one near the radiator fans is for the engine, the one on the right side near the battery is for the intercooler.
Read the coolant temp sensor with an OBD scanner.
An inexpensive bluetooth model can do the job.
If the temp seems to jump up and down instantly it’s probably a bad sensor or failing electrical connection.