'Check Coolant Level' OBC message

[supertack]

I keep getting this intermittent 'check coolant level' message, but every time I check the tank, it's already full. My first guess was the sensor, but I had the radiator & thermostat replaced last year, & I would assume the sensor woulda been replaced with the radiator.

[Jeron]

I replaced my float sensor years ago and it didn't fix the problem.

Others have identified the problem as a crack/break inside the expansion tank. I noticed a piece of loose plastic inside my tank last time I flushed it so I suspect that the broken expansion tank is the problem.

I think it was discussed here a few weeks ago. I also think I've heard of one person that has fixed the problem by replacing the tank but I cant be sure.

[Wayne 962]

Originally posted by supertack
I keep getting this intermittent 'check coolant level' message, but every time I check the tank, it's already full. My first guess was the sensor, but I had the radiator & thermostat replaced last year, & I would assume the sensor woulda been replaced with the radiator.

Nope, the sensor is not typically replaced with the radiator - it's in a separate area. Also, this may be a sign of bubbles or air pockets in your system, as the coolant level may be low while you're driving and then pop back up again when at idle.

I would replace the sensor, and then rebleed the entire system, and that should solve the problem. If not, then you'll have to investigate further...

-Wayne

[supertack]

Where is the sensor located, & how accessible is it? Any tech article on the job, or is this gonna be another plug to buy your book?

[Jeron]

The sensor is at the bottom of the reservoir. It has a big plastic nut holding it in that simply screws off. It wont hurt to replace it but I don't know of anyone that has solved their problem this way. The new reservoir comes with the sensor, IIRC.

You may need to remove the lower rad hose because it interferes with removing the sensor so be prepared to top off with a 50/50 coolant mixture. And make sure you use the same coolant otherwise flush the whole thing.