I recently bought my 1990 300D. The radiator light illuminates periodically for no apparent reason. She runs at about 82 degrees and there are no leaks in the system. The coolant level is where it should be. The light will come on and off intermittently.

The previous owner took it to a mechanic who replaced the thermostat and radiator cap which did not fix the problem.

Any ideas?

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1990 300D - 171K miles
http://nrl073.googlepages.com/DSCN66...646-medium.jpg http://nrl073.googlepages.com/DSCN66...654-medium.jpg

The coolant level sending unit in the expansion tank needs to be replaced. Mark

Is the part I need? Coolant level sensor?

http://catalog.worldpac.com/mercedesshop/sophio/wizard.jsp?partner=mercedesshop&clientid=catalog.mercedesshop&baseurl=http://catalog.peachparts.com/&cookieid=24D0VHTBF24R0HGP80&year=1990&make=MB&model=300-DT-003&category=G&part=Coolant+Level+Sensor

__________________
1990 300D - 171K miles
http://nrl073.googlepages.com/DSCN66...646-medium.jpg http://nrl073.googlepages.com/DSCN66...654-medium.jpg

That's it. Be sure to install it right side up (pay attention to the orientation of the part you removed). Mark

Thanks for the help.

__________________
1990 300D - 171K miles
http://nrl073.googlepages.com/DSCN66...646-medium.jpg http://nrl073.googlepages.com/DSCN66...654-medium.jpg