Help: Error messages

[Al Gray]

I have recently got these messages on my 1992 525i:

1. Coolant level +

2. Brake linings ( brakes, calipers and sensor wire were replaced on rear; front brakes were done a year ago. I checked the linings and they were fine)

3. Oil level sensor

Any ideas on how to correct them would be appreciated. The coolant level appears to be correct and the oil level is full.

[Jr ///M5]

Tap on the bottom of the oil pan, the sensor is stuck, it's where the three bolts surround a circular disc. This should clear the oil sensor problem.

Try tapping the coolant level sensor in the same manner, be gentle now, it's located near the top left hand part of the radiator and as you know, the radiator and associated fittings are brittle. It's actually screwed into the radiator. A slight tap could dislodge something that is causing a short, or disconnect the wires and give it a shot of contact cleaner. If it still fails to clear the message, you'll have to swap the sensor on the fly after the engine has cooled down overnight. Use teflon tape to help get a good seal, but don't overtighten!

The sensor wires are shorted in the brake circuit. You will have to pull the calipers and check the pads to see if the contacts located in the inboard pads are worn down or broken. If not, disconnect the sensor wire at the coupling and clean the connection with a spray contact cleaner and reconnect. The sensors are located at the drivers side front and passenger side rear.

Hope this helps,
JR

[DaveVoorhis]

Re the coolant level warning: On a 525, the coolant level sensor is located on the underside of the expansion tank. You can see its leads if you remove the air duct for the alternator. The connector may be corroded, or the float may have popped off and be floating at the top of the expansion tank, or the sensor may have failed internally. Road salt and water sometimes gets inside and dissolves the internal wiring.

A bunch of warnings, without associated failures, may also be due to a low battery.

[Al Gray]

Re the coolant level warning: On a 525, the coolant level sensor is located on the underside of the expansion tank. You can see its leads if you remove the air duct for the alternator. The connector may be corroded, or the float may have popped off and be floating at the top of the expansion tank, or the sensor may have failed internally. Road salt and water sometimes gets inside and dissolves the internal wiring.

A bunch of warnings, without associated failures, may also be due to a low battery.

Because we are making some repairs the car has been garaged and not driven much. I just had to charge the battery again today because it was low. Also, if I recall correctly the battery is probably 4 - 5 years old. Maybe it is time to replace it. I will still perform the checks that you recommended. Thanks for your help

[Al Gray]

I will follow your suggestions and hopefully clear up these problems. It never ceases to amaze me how helpful everyone on this board can be.

Al Gray

Tap on the bottom of the oil pan, the sensor is stuck, it's where the three bolts surround a circular disc. This should clear the oil sensor problem.

Try tapping the coolant level sensor in the same manner, be gentle now, it's located near the top left hand part of the radiator and as you know, the radiator and associated fittings are brittle. It's actually screwed into the radiator. A slight tap could dislodge something that is causing a short, or disconnect the wires and give it a shot of contact cleaner. If it still fails to clear the message, you'll have to swap the sensor on the fly after the engine has cooled down overnight. Use teflon tape to help get a good seal, but don't overtighten!

The sensor wires are shorted in the brake circuit. You will have to pull the calipers and check the pads to see if the contacts located in the inboard pads are worn down or broken. If not, disconnect the sensor wire at the coupling and clean the connection with a spray contact cleaner and reconnect. The sensors are located at the drivers side front and passenger side rear.

Hope this helps,
JR