Coolant Recover Tank level sensor burned up!

89SCfan

Registered User
Anybody hear of this happening? This morning I started my car in the garage and was sitting there for a minute to let it warm a bit while I put on my seatbelt and tuned a radio station. I look up to see a wisp of white smoke coming out of the passenger side gap between the hood and fender. As I'm looking it continues to increase and looks like someone blowing a plume of smoke from inside the engine compartment. ~~~?! So turn off the car, pop the hood to look around and don't really see anything obvious. So I start touching wiring harnesses and connectors when I notice the level sensor for the coolant recover tank is warm. I pull the sensor out and find the tank is filled with white smoke. The bottom of the sensor, under the cap, is hot and melted. The black potting material is melted and gooey. So I disconnect the sensor so it doesn't catch fire and put the sensor back in to keep the coolant from sloshing out and drive the car. All else seems OK. I looked online but can't find a replacement for the tank level sensor. Anybody know if NOS are still available or am I looking at finding a used one?
 
I've seen the stalk break it's overmold/sheathing, exposing the wires inside. Sounds like that what yours did and driving around must have made the stalk flop around and twisted/abused those wires until they shorted out.

What is the light doing on the VMM? Should be on with that sensor unplugged...wait a bit when testing so the system can do it's checks, etc.

I might have a used spare to sell if you need one. Early style, I have both short and long stalk types. PM me if interested.

Ken
 
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I've seen the stalk break it's overmold/sheathing, exposing the wires inside. Sounds like that what yours did and driving around must have made the stalk flop around and twisted/abused those wires until they shorted out.

What is the light doing on the VMM? Should be on with that sensor unplugged...wait a bit when testing so the system can do it's checks, etc.

I might have a used spare to sell if you need one. Early style, I have both short and long stalk types. PM me if interested.

Ken

The stalk is intact, not broken or loosing any sheathing. Although it did get a little deformed right where it goes into the cap assembly due to the heat. The VMM light is showing normal condition (green) for coolant level. I'll let you know about the spare when I decide how I'm going to proceed.
 
Can you tell if coolant made it's way into the bottom of the top part where the stalk is cemented in place?

Might want to remove it and ohm out the probes to see if the short is contained at the sensor.
 
If memory serves, that sensor is made to complete the circuit by using the coolant (hence...when no coolant, circuit breaks...warning light comes on)...so it's made to operate in presence of and submerged in coolant. That's very odd...i have a feeling something else is going on. Unfortunately I don't know what that could be.
 
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