Any ideas as to why my coolant light keeps coming on?

After running a few short trips around town the coolant light comes on, flashes a few times and then goes off. The fans kick in big time.

Then I leave the car for 45mins, start the car again the light and fans come on again. I turn the car off, leave for a few more mins and turn it back on, but this time no coolant light pops up and no fans come on?

Coolant level is fine so there is no coolant loss and when diagnositics run on computer by mechanic no errors come up?

Can anybody throw some light on what the problem could be?

 

check you connections to the radiator fan and condensor fan also your ect sensor. could be a loose connection or high resistence on a connection. does it happen after you hit a bump or anything? also if it doesnt stay on then it shouldnt be that big of a deal obd II only stores codes if it happens enough to be a problem.

running hot?

 

Thanks for the tips. Temp has touched above 90 only very recently but taking it in tomorrow to a non audi "take your mother and your money as a payment" mechanic for a view. Will keep you posted as to the outcome.

Bumps and humps in the road are not an issue. All pretty flat around here.

 

Maybe a bad temperature sensor, which is an easy fix.

 

Haven't had a chance to get the car in to get it in to the garage over christmas but when I spoke to the mechanic he suggested it could be the sensor. Will go down that route and see how I get on. Cheers for all the advice. I will post again once sorted...fingers crossed.

 

Which coolant light is coming on? If its the low coolant level light thats coming on and the coolant level is good you need a new coolant expansion tank which the sensor is in. The CTS sensor won't cause any coolant lights to come on. I have no idea why an audi mechanic can't figure out something so easy to diagnose.

P.S a bad sensor in the coolant expansion tank won't have any fault codes.

 

Hi there mate, I am experiencing exactly the same problem with my Audio 2003 FSI, did you manage to resolve the problem?

 

Just got the car back from the garage where this time the coolant light issue did come up on the diagnostics and hopefully problem is sorted after spending£250. I had the temp sensor on the engine replaced as the fans were kicking in but the engine temp was not rising suggesting a faulty engine sensor, not a faulty coolant tank sensor as this would not have triggered the fans to kick in. Note: if the problem is sporadic it may not store in the OBD as if it does not reappear after turning the car on and off something like 16 times, the OBD clear's the fault.

 

Thanks for the feedback - sounds like I may have the same problem, sometimes in the morning when I start the car with a cold engine the coolant light comes on and the fans go balistic! I will try and get the temp sensor on the engine replaced and see what happens.

Will you let me know how yours is doing.

Many thanks,

Dick Muller (New Zealand)

 

It sounds very similar to the problem I had. Haven't had a chance to test the car out properly yet as I don't really use it during the week but if you take your car in and run diagnostics it should come up as a problem with the sensor on the engine. I will post again if the problem is not sorted but hopefully all is good now.