Viewers may recall my posting some months ago about the saga surrounding the sad passing of the viscous fan coupling on my 505 GTI. I fitted a second-hand unit and started getting a loud growling sound that came and went, seemingly randomly, when the engine got hot on warmish days. The sound was not apparent under the bonnet, only in the cabin. Well it wasn't the coupling, it was the alternator. Another of those bloody coincidences designed by the Norse car god (Volvo?) to throw red herrings at unfortunate motorists.

The rectifier had an intermittent fault in one phase. This has an effect similar to instantaneously adding and subtracting half kilogram wheel weights to a wheel traveling at 100kph. No wonder it was growling.

It finally died permanently one dark Sunday night in Geelong while travelling from Warragul to Warrnambool. Suddenly, a quick growl and then no battery charging. At least I finally found out what was causing it. Would have been nice though had it happened the previous Tuesday as the car was in bits on the Wednesday having the timing belt done.

So if you get the growl, check the alternator.