I faced the same problem last year and my radiator went kaput. It burned a 18k hole in my pocket. Please dont drive once the engine overheats.
Its happening again after almost one year. I showed it at the service center, he says that there is no problem but I know there is a problem.
This is my theory
- The AC compressor is 150cc; the biggest of the lot and so this may have a direct bearing on the radiator switching on. There are 2 stages of fan speeds (?) in the radiator. The loud sound comes when it runs in stage 2
- The dust that accumulates in the fins of the radiator is not cooled properly and so the cooling of the coolant is not effective which in turn means the temp sensor always has a higher value and the fan does not stop.
You need to go the service center and sit on their head. This is what I intend to do