Flashing Coolant Light

[Richard Bruce]

I have developed a slow flashing coolant light, which I understand equates to either a coolant level problem or a engine compt. fan. I have confirmed my coolant level is correct.

My question is, how do I check the operation of the engine compt. fan and is there a way to check the coolant level sensor? I do not own a durametric to run the fan.

Thx in advance. This is an 02 base.

[Uller God]

This same thing happened to me. If you turn off the ignition after driving a few blocks then re-start the car does the flashing light go off? My coolant level was spot on as well, I just needed to add a couple tablespoons of coolant and took care of the problem.

[JFP in PA]

Originally Posted by Richard Bruce

I have developed a slow flashing coolant light, which I understand equates to either a coolant level problem or a engine compt. fan. I have confirmed my coolant level is correct.

My question is, how do I check the operation of the engine compt. fan and is there a way to check the coolant level sensor? I do not own a durametric to run the fan.

Thx in advance. This is an 02 base.

You will need either the Durametric system or access to a PIWIS unit to test the engine compartment fan without taking the car apart to manually test the fan.

The coolant level sensor is located at the bottom of the surge tank in the rear trunk, and can be accessed by pulling the carpet back. The rate of the flashing light also will tell you what is up:

"Four functions of the coolant warning light:
1. Engine coolant level too low -- light flashes slowly (0.5 Hz)
2. Engine compartment temperature too high -- light flashes slowly (0.5 Hz) (engine compartment blower might be faulty)
3. Engine coolant temperature too high -- light is lit; pointer on the right
4. Temperature sensor at water outlet faulty -- light flashes rapidly (1 Hz) ; pointer on the right

[Richard Bruce]

Thx guys for the response, I actually did try to reset it by shutting it down and starting it back up, no help. I have determined it is flashing slowly (1 flash every 2 secs.) so this leads me to either the coolant sensor or the engine fan. I was curious if there was any test procedure with perhaps an ohmeter that I could check the coolant sensor. And by the way does anyone know how the coolant sensor detects level when it is not physically emersed in fluid?
Thx in advance

[JFP in PA]

Originally Posted by Richard Bruce

Thx guys for the response, I actually did try to reset it by shutting it down and starting it back up, no help. I have determined it is flashing slowly (1 flash every 2 secs.) so this leads me to either the coolant sensor or the engine fan. I was curious if there was any test procedure with perhaps an ohmeter that I could check the coolant sensor. And by the way does anyone know how the coolant sensor detects level when it is not physically emersed in fluid?
Thx in advance

Again, either the Durametric system or a PIWIS can directly read the water temperature sensor while it is still in the engine.

[Richard Bruce]

Correction on my last post, the slow flashing light leads me to the coolant level sensor or the engine fan.

[clickman]

See here for explanation of how sensor works:

How the coolant tank sensor works

[jeffm]

I had a slow blinking coolant light turn on after having the overflow tank replaced on my 911. The dealer (non Pcar) had some random shop replace the tank prior to delivering the car. I chased around the coolant level, attempted to purge air, replaced the cap, etc... for well over a week. Brought it to my Indy and the dx was a bad sensor.
The sensor is not part of the replacement tank and I believe the previous shop damaged it while replacing the tank.