Gary R.

Hoping someone has seen this and solved it. When the car is cold and started first thing in the morning the temp gauge almost immediately buries itself at 250F and the "Low Coolant" message comes on. As we know the coolant level/temp is fine we keep driving and once the coolant temp really gets to about 150+ the gauge drops to show that temp and the coolant warning goes out. All is well after that and she never runs over 175F. Had shop run a quick diag, showed no issues, had them put in a new temp sensor just for the hell of it. Still doing the same thing, any ideas??

BillC3

Are you sure the coolant level is okay? It sounds like your coolant level is dropping overnight, exposing the sensor inside the coolant passage. Then, when the engine warms up, the coolant expands and covers the sensor. Maybe there's a leak or crack in the part(s) where the sensor is installed.

badabing

Have you done any work to the cooling system recently? You may have air in the system.

I had some work done to my car and the tech left a hose clamp loose and I lost a couple gallons.

The process of burping the system to get the air out was tedious. Took almost a week of running the car, letting it cool etc.

During that time the gauge would go back and forth showing normal temp and overheating.

The heat in the cabin would also go from hot to ambient temp.

Gary R.

Bill and Bada -

Left the car with my shop while we were on Vakay. It turns out the level was just low enough after he did a flush (not enough "burping") that the low level sensor would trip when cold. Apparently that sensor will send the gauge to max along with tripping the low coolant light. All is well now!