Decelerating Whine

[ttwolf]

Since I have owned my XC70 it has had a very distinct whine as I am decelerating. The whine is louder when the weather is cold but still loud even in warm temps. At right around 20 MPH when I am braking or just coasting it starts a loud whine that sounds from the front of the car. It sounds until I am stopped and only happens when decelerating. I am baffled as to what it could be. At first I thought it may be the turbo but I am now thinking it maybe something with the differential. But to be honest, I have no clue. Any help with this issue would be very much appreciated.

[pjg01930]

Experiencing a similar whine in my '00 XC (142K). Started about six months ago, same time I had a new alternator installed? As it has gotten colder more noticeable. Most noticeable on mine at 35-45mph, let off gas and decelearate and can be pretty loud sometimes (although inconsistent - really loud sometimes and others not that loud). Sounds similar to a wheel bearing noise, but not consistent and hasn't gotten any worse/louder.

[8pack]

Check the fluid level in your Bevel gear. There is a fill bolt on top. Remove it and stick your pinky in up to the 1st knuckle(if it fits!) or use a bendy straw as a dipstick. If you don't come out with oil on your pinky or within a few centimeters if the bottom of the fill hole you are low on oil.

Could be transmission also, but the bevel gear is the easiest thing to check and you should check it anyway as they tend to weep. If low, suck the old fluid out with a plastic hose and simple vacuum pump and refill the same way with 75/90 synthetic gear oil. You don't need to buy the Volvo stuff. Mobil or any other quality brand is fine.

You should do this anyway as a matter of course given the miles on your car..........