LOW COOLANT Warning Light

[MSG2004]

Hello,

My 53 plate, 180k, Auto - the low coolant warning light came on a few weeks ago as i drove the 2 miles to work, took about 15 mins, weather was cold - checked collant, it was at the right level.

The same thing happened yesterday, approx 4 mile drive,a bit warmer and 15/20 min drive - light came on when i switched off as before.

About 6 months ago, it came on whilst driving on the motor way at about 70 mph for an hour.

About 2 years ago, stuck in traffic on a hot day, the low coolant light came on and temp was high, so i turned on fans and temp went to normal - as i was going to the dealership for a service, they said as i expected, nothing wrong and car then was inder warranty.

Model W203

All help appreciated.

Thanks

 

[dava]

Sensors are prone to go, located in the top of the header tank.

 

[MSG2004]

Thanks Dava -is it a relatively easy job to replace? How much fr the sensor, approx?

BTW - engine normally runs at around 90

Thanks

 

[panason1c]

I hope it is only a sensor gone in your case........i had a similar problem with the coolant light intermittently coming on and then off for no apparent reason...coolant level fine, engine temp fine.....it turned out to be a faulty fan control unit costing £550!
(the new control unit came complete with the large electric fan as one unit)

 

[GMK]

Had the same intermittent problem on my SLK200. Dealer couldnt identify the fault so it remained for 3 years (!!). I just leared to ignore it and use the temp guage...

 

[panason1c]

Had the same intermittent problem on my SLK200. Dealer couldnt identify the fault so it remained for 3 years (!!). I just leared to ignore it and use the temp guage...

Do you still have the car?.........i eventually noticed on mine (with the engine at idle) that during the time the coolant lamp was lit the large electric radiator fan would be stationary when it should be turning...when i gave it a 'spin' by hand it would try to continue spinning in an erratic fashion.........i renewed the fan and control unit and that cured the problem, no more coolant light and a properly working rad fan.

 

[MSG2004]

Hello Panasonic1

Did your car overheat?

BTW, what is the normal running temp for the 180k auto?
Thanks

 

[panason1c]

Hello Panasonic1

Did your car overheat?

BTW, what is the normal running temp for the 180k auto?
Thanks

Nope, it ran at a normal temp of around 85 degrees.....the light would randomly appear for no apparent reason whatsoever (due to a faulty fan control unit), The reason i never overheated was that the fan fault was intermittent and didnt keep the fan stopped for long enough to cause overheating which, anyway, would have only been a problem if i was stationary for longish periods and with no airflow through the rad.

The normal running temp is around 85 degrees but it is also normal to see 90+ degs during high ambient temperatures or if the engine is working hard....ie = climbing a long hill or towing a trailor, etc, though i wouldn't be concerned if yours has consistently run at 90 degs during normal driving, it might be just a difference in the temp sender calibration or whatever but 90 degs is certainly within a 'normal' range.