Coolant warning light comes on while driving

[zhaniaudi]

I've experienced the red cooling warning light coming on after driving my B7 S4 Q25 for about 30 seconds after starting from a warm engine. This has happened twice in the past couple of weeks. In both cases the coolant level was near max and the oil level was reasonable (recently checked in other words and found to be ok). Both times also happened on warm to hot days, late afternoon time frame. Temperature gauge indicates normal engine temperature when starting the engine.

I'm wondering if there's a latent heat issue with the car where the coolant continues to warm up once the engine has been shut off since there's no fan/air movement to cool it down. Then when I start the car up a few minutes later and drive off, the coolant temperature is higher than it should be, hence the warning light. In both cases the car was fine after I let it cool down. In other words, no warning light appears and when starting the car the next morning.

Has anyone else experienced something similar to this? Is it indicative of an issue such as a faulty sensor or just what I described above?

[vacsimile]

Make sure the coolant reservoir is plugged in good (connector is on the under side). You could have a bad coolant level sensor. Or for some reason your coolant isn't conductive enough for the sensor to work

[Justincredible]

Make sure the coolant reservoir is plugged in good (connector is on the under side). You could have a bad coolant level sensor. Or for some reason your coolant isn't conductive enough for the sensor to work

I would say the same thing. Check the wires. Pull the plug out and clean the contacts and put the plug back on the coolant container.

[zhaniaudi]

I would say the same thing. Check the wires. Pull the plug out and clean the contacts and put the plug back on the coolant container.

OK, thanks. Will check this out this weekend.