After stopping the engine following a 20-mile journey, I noticed a whirring sound from under the bonnet. Closer inspection revealed that this noise seemed to be from the upper part of the engine, forward of the air filter location. It was accompanied by the sound of water trickling into the coolant reservoir - perhaps overflow?

This eventually stopped after a few minutes.

Engine coolant temperature as indicated was normal, so I don't think this was an overheating issue. Does anyone out there have any experience of this "symptom"? Would it be advisable to have this checked by my local dealership?

Sounds like fan running, possibly had been doing some emissions cleaning 

 

The other possibility is thermostat opened and some water circulated where there had been airlock (which explains the trickling).  When it is cold check the coolant level and top up if required.

My Monte Carlo does the same, apparently the TSI petrol engines have water and oil cooling on the turbo with run on after switch off. Read that elsewhere on Briskoda.

Thanks, Tintowellfan. Your explanation makes a lot of sense. (By the way, I asked my local dealership to check the issue out during a minor service last week. The response was that they had checked the vehicle for faults (none found) - but they offered no explanation of the likely cause of the "whirring/trickling" noises

No problem, glad to help. No surprise regarding dealership, I am at an age where years of bad experiences with dealerships, of any manufacturer, have left me totally cynical. Modern day car technicians are not old school mechanics, if the computer cannot diagnose the problem they have no clue. Old school mechanics use their brains and years of experience, but unfortunately modern cars now have so many computer controlled systems that even the best mechanics are now struggling, sadly. 

Edited 18 June, 20232 yr by Tintowellfan
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