every now and then when the wife's FD is started the low coolant light/buzzer goes on. popping the cap, the coolant is right at the top. after a while it will go out.

go for a drive and it might sound off again, but when the AC is turned on it always goes out.

the coolant seals are fine, the motor is fine, no coolant out the exhaust etc...

what's weird is the sensor going off when i am seeing coolant up to the top of the neck.

any ideas what's happening?

thanks,

howard

 

Any chance the "Overheat" (exhaust system) light and/or the oil level light is flashing in synchronism with the low coolant light? If so, the problem might be on the white wire with black stripe running to the alternator's voltage regulator section. If not, the wiring diagram section C-1a would indicate a problem with the coolant level sensor itself, or possibly the wiring from it to terminal 3D of the instrument panel connector C1-01. I have no idea why the wiring diagram shows the coolant level sensor as an analog device. It's either covered with coolant or not. Should be a switch. Maybe there is contamination on the sensor element that prevents reliable sensing of coolant?

 

Did you check your belt, because I had the same problem. I changed the water sensor three times and kept checking the coolant, until I just tighten the belt and that did the trick! I guess it wasn't spinning the pulley fast enough, but that with a greddy pulley kit.

 

Possible that the either the sensor is corroded and not conducting good or maybe the coolant isn't conducting electricity good enough? I know mine it just grounds out via coolant to know when the coolant is full.

 

My FD had the exact same problem earlier this year. I ended up replacing the coolant level sensor, and wiring harness pigtail(aka cutting/splicing) with another low mileage one in better shape, and I haven't had the problem since. Not sure if this will work for everyone, but thought i'd put in my 2 cents.

 

I vote bad sensor

 

A local buddy had the same issue. I gave him another sensor from my spare engine and the problem went away.

 

thanks. i appreciate all responses and will replace the sensor. fortunately, it is about the only thing on wifey's unmolested FD that is serviceable without pulling the motor

howard

 

Be very gentle when you install the new one - it is very easy to crack the plastic sensor body with too much torque.