[marsdalebear]

I am convinced that the whistle from my engine is due to gear wear in the balance module. Comparison to the audio files on youtube is identical.

Unfortunately the Volvo dealer can only confirm by replacing the unit.This at a cost of £828 incl VAT. This is for the module and 3 hours labour.

The labour time of 3 hours suggests that it is just a case of dropping the sump, removing old module and replacing with the new one.

My question is , are there no alignment or backlash checks on the mating gears?

As the car is out of warranty, purchased from a non franchised dealer and serviced by an independant, there is no chance of Volvo contributing anything, and to be fair, I was expecting a far longer labour time and higher price.