I've recently noticed a hum on my 1996 850 Turbo wagon.(67,000 kms) It seems to be coming from the left front, and the pitch changes according to the speed I'm travelling. I thought it was my summer tires/wheels so I changed over to my winter set. The noise is still there. It's not really loud, but I notice any little odd noise. The car is an automatic, I've taken it out of gear while it's making the noise, but it doesn't change. Does anyone have any ideas what it may be?<BR>My other question is regarding a block heater. I brought the car from Eastern Canada to Western Canada, where the winters are much colder. Volvo quoted me $85 for the part and $125 to install. Is it a big job? Is the part specific to the car, or are they pretty generic?<BR>Thanks evertone.