Coolant Sensor

[winstontj]

Is there something I'm missing? I'm about 99.999% sure that I've got a coolant leak through the head gasket into one of the cylinders. Water has been dissapearing from the fill tank about a cup every 500 miles or so. I've been filling it up a cup at a time when the coolant light on the dash/roof flashes. Today the light came on like usual and I filled it after letting the car cool for a few hours only this time when I restared the car the light didn't go off.

Is there a reset or something I'm missing? There is plenty of coolant in the system. There is nothing crazy like water & oil mixing so this is very straight forward. Should I check anywhere else for a coolant sensor? Would it be worth anything to check the sensor in the top of the fill tank? I assume this is what is triggering the light?

Any thoughts or help would be appreciated.
Thanks,
TJW

[Dave]

Yeah - its the sensor in the plastic overflow/fill tank. They go bad from time to time.

[PiercedE30]

Yea, that sensor can go bad. All it is is a magnetic trigger. The coolant itself actually destroys the sensor itself leading you to replace it.

[FredK]

Just curious, do you have any white residue on your plugs?

[winstontj]

white plug residue

Just curious, do you have any white residue on your plugs?

the car is only a few months old & I replaced the plugs ~3,000mi ago. I plan to pull them & post up some pics soon. No idea though why? I plan to find one or two that are different than the rest, if not maybe its not a head gasket...

[Turf1600]

Winston, replace the sensor. You're putting in too much coolant and it's pouring out of the overflow tank. Mine does the same..