RyanPerrella

Dammit, I so wanted to get rid of this annoying message.

While the engine was out I pulled the coolant reservior and replaced the coolant level sensor with a used one from 928Intl. When I pulled mine it had no float, it was completely disintegrated. So I thought, THIS is obviously the problem. Cool, so i have the used one from 928 INTL and it looks great, nice, still hard float and i think all is well.

I installed it 2 weeks ago but just tonight i finally got the car together and had it running again finally. But sure enough i see the damn "check coolant level" message again. WHY???? I previously replaced the coolant pressure sensor when it split and fell apart. That was new, now what can be causing this message?

The car is full of coolant, its above the cold mark at this time cause i still suspect there is air in the system and there will be until i get a 100 or so miles on the car.

The sensor seems simple enough, its a float, it trips a switch and it should be good. So how come i am still getting this message? Is the sensor bad, any ideas?

mj1pate

Ryan;

I haven't got to the juncture of replacing this sensor yet, but I would disconnect the sensor connector and see if you stiill get the message. Something I've discovered in my tour under the air cleaner, in my still-recent ownership is heat and chafing are taking a toll on connectors and cables. I've found too many crumbling connectors, chafed and bare boots and so forth under the hood. I'll bet you have a short on the engine coopartment side. Good luck....

Mike

mj1pate

This taking in consideration that the coolant level alarm is normally open, which it probably is.

SwayBar

Did you 'burp' the coolant system by squeezing on the radiator hoses as it's warming up? If not, that will purge the air pockets.

mj1pate

Good point...most cars have a bleedng point somewhere for this purpose. Is there an identifiable bolt near the top of the engine that is used for this?

Mike Frye

As Swaybar said:
You can help things along by leaving the cap off of the reservoir and squeezing the radiator hoses at the front of the engine while it's running. You'll hear it gurgling.

When you filled it up did you just use the reservoir?

When I did my TB/WP I read that it's easier to get the coolant in if you leave the top of the rad hoses out and fill through them, then put them on the engine and top it off using the reservoir. This way you're more likely to get all the air out and fill everything in the block before turning it over. The WP doesn't like to be run dry and it doesn't take long to ruin the seals if it is run dry.

Once you're sure all the air is out, if you still have a problem it may be time to break out the multimeter. It's either the switch or the circuit.

Imo000

You can actually check the level sender to see if its working. Connect an ohm meter to it and, if I rember right, when the float is down it will close the circuit. OR maybe its the other way around, but regardless, you should see a chage at one of the ends (top or bottom).

heinrich

Ryan the level warning is ONLY from the reservoir sender, nowhere else, so burping makes zero difference. The sender as Mike Pate suggests, is your first point of troubleshooting, and you should do as he recommends and disconnect. Then short the connector. I don't think the warning is instantaneous.

Mrmerlin

you might get a good looking used sender but they can fail internally and still look like they work, check the connections first if it still gives no joy reconnect the old one and see if you can make it close the circuit. There is no need to BURP a 928 it has a self bleeding system the only thing that you need to worry about is filling the heater core, this is best done by turning on the heater and taking the car for a drive of about 5 miles this should fill the heater core and purge any other air from the coolant system. The self bleeding ports are on the top driverside of the radiator and the center of the water bridge( the small line that comes out and connects to the resivour) I had a similar problem with my sender i got a used one and it looked good , after having it give false warnings I bought a new one plugged it in and all is well

Tom. M

It does work instantaneously. When my water pump started leaking..I didn't know until the warning came on (89 digital dash). Filled with water..and short time later...came on again as it sucked in the water. Filled yet again...until it would take no more...

After the waterpump replacement..filled as much as I could...3 gallons...or so...and then drove home..and the low coolant warning came on again..got home..topped it up..and good to go...got about 4 gallons in there..(give or take a few pints)...not too bad in a 4 gallon system ..

Later,
Tom

Bill51sdr

I believe in '89 and newer cars, there is a pressure sensor connected to the small vent hose that goes back to the reservoir. The sensor is just behind the shock tower, passenger side. I do believe if that sensor is disconnected or otherwise faulty, it will cause a low coolant warning. I would look there as well.

JP Rodkey

Good call, Bill. I've had that switch cause the light to come on in several cars. It's been written up (I think Wally contributed) elsewhere and a search should get results.

rcoble

Ok this may be a well known thing , but:
I have now had 2 people send me bad coolant level sensors. I was fiddling with one at my desk, took a pair of pliers and pulled on the electrical connector and woo hoo! It comes apart! Just soldered in a new wire and this time I filled the tube that it sits in with epoxy so it won't corrode the wires in half again.




(re-post)

RyanPerrella

Bill,

I replaced the pressure sensor a year ago.

Rcoble,

Yeah i guess the sensor is just not working, I guess I will just buy a new one rather then the used route.

RyanPerrella

I just checked my old one that had the destroyed float. I am glad i didnt throw it away come to think of it.

Its wire is in good shape, I guess i will loosen the coolant tank bolts and try and pull the sensor and sway electrical components.