Passat coolant light is on

Jan 26, 2005 8 Replies

My VW Passat coolant light (the one that looks like a thermometer with a wave under it) came on during the cold snap the other day and came on again today (it's very cold out again today).


1) On both occasions the radiator was full and the overflow level was where it should be in that plastic thing.
2) The car did not overheat. As it heated up, the temp gauge went up slowly as it should.
3) When I turned the car off and on again, that light went out.

My plea for answers:


1) What could cause this?
2) What should I do about it?
3) Is this causing damage to my car as long as the car does not overheat (or, can I just forget about it and drive as usual)?


Thank you for any assistance, Judy


Is it where it should be when it's cold or warm? It expands slightly when warm so if the coolant is a little low when cold, triggering the light, and then when you actually check it it's warm (and the level higher), that could be the problem (low coolant but not obvious). Check the coolant level and add coolant to the 'max' line when it's stone cold (sitting overnight) and then see if that works. VW's coolant light senses a low coolant level and it's very sensitive to it...the slightest bit low when cold can often trigger it.

if a low coolant level was your problem, correct it but keep an eye on it. If it keeps going low you have a leak somewhere.

VWs are usually that way...they're programmed that once triggered the light stays on until you turn the ignition off and on again.

I believe that VW has a "warning" that illuminates if the temperature is right for ice to form on the roadway ... but I'm not positive. Might want to check the owner's manual and see.

Also some cars have a *blue* light that lights up when the engine is cold, but I believe that's only ones without a temperature gauge. I remember getting a NB as a loaner once that had that light. I've never seen a low temp warning on a VW but it is common on some other German cars so they might have put it on the Passat.

nate

Erik Dillenkofer wrote:

for ice to form on the roadway ... but I'm not

that's possible (our BMW 3-series has that) but I doubt it'd be shared with the coolant light.

Coolant level sensor on the expansion tank. Mine went a while ago. It would beep & the light would come on on a cold start & then it would go out when the car reached operating temperature. If it is this you need to change the whole expansion tank - you can't just change the sensor. Its not terribly expensive.

I.

The light on my 01 Beetle TDI came on immediately after starting the other day, and it was maybe 15 degrees. I turned in so the sun was on the hood, shut it off for awhile and it was fine when I tried it again.

Geez I hope I am not posting this twice. I find the "reply" function a bit confusing.

I just want to say thank you to everyone for responding. You reassured me that I am not putting my car into any immediate danger, but I guess I need to go check things out with my mechanic.

Regards, Judy

jwlbal wrote:

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