[cruzmisl]

HI All,
The coolant lamp on my 2005 NB convertible is acting up. This morning the car was cold and the light was red with a corresponding ding. That's weird since it's usuallyblue when it's cold. Apparently the red indicates overheating but that's obviously not the case. If I turn the car off/on it will go out but the problem will return infrequently. The coolant level is good and all fuses are good.

Any ideas on how to fix it? Could it be a faulty temperature sensor?

Thanks,
Joe

 

[jfoj]

Could be the coolant sensor in the expansion tank and/or the coolant temp sensor.

I believe the coolant sensor is probably cheaper and easier to replace and on the older cars has been a known problem.

So if you can find the coolant sensor cheap, might want to start with that??

At least in my 2003 1.8t it appears the expansion tank has some sort of metal sensors that somehow detect the coolant level? Some cars may have some sort of float?? Not sure what the 2.5 has as I have never had my hands on a 2.5 car yet.

 

[cruzmisl]

Thanks. I'm hoping it's something simple. Car only has 45k miles. Would the dealer be able to scan it and find out what it is? I have to pass an emissions test and don't want this to affect it (if it does or not who knows)

 

[Smileybug]

Make sure the coolant level is well above the min line. If its anywhere close, it can trigger the light on cold mornings.

 

[jfoj]

Cruz,

Where are you located and what are your morning temps??

Coolant will contract when cold, check the coolant level first thing in the morning and make sure it is about at the seam on the expansion tank.

If low, do not add just any antifreeze, get some from VW or an import auto parts store.

 

[cruzmisl]

It was pretty cold this morning ~30f. Can I just add a bit of distilled water? It's at the low level mark now. Then I'll take it for a ride and get it all mixed up so it doesn't freeze? It's a small amount so I can't see it changing the freeze point significantly

 

[jfoj]

You should be able to add a cup or a pint without significantly changing the freezing point.

If it is right on the low side of the level, then this is likely the caused as the level may drop with temp and when you drive the car the coolant may slosh a bit and trigger the low level alert?

 

[cruzmisl]

Topped up the coolant level and voila! No more lights.

Thanks a ton for the advice!!