I am about to purchase a Volvo S40 but am a bit worried by a noise that seems to be coming from around the Turbo. This noise is very metallic and is heard quite noticeably when the throttle is released, rather like a small tang of metal bouncing on another metal surface. The noise is quite low in frequency (unlike what I would expect from turbine blades hitting the housing) and is not due to any vibration on the heat-shields (I've poked them with a stick when the noise is present!). I would guess that the noise is due to some problem with the wastegate, but that, is just a guess. A few 'ting's' can be heard randomly during increase and slow decrease in rev's but is when the throttle is quickly released that the noise is very noticeable.

I have been informed that the 'turbo must be replaced as a unit' and even if the problem is only confined to the wastegate it would still mean the replacement of the complete turbo unit. The car has always used quite a lot of oil and at tick over a fetching blue haze is in evidence. Mileage is 137,000 with full, on-time Volvo servicing.

I would welcome any advice on the source of this noise and any advice on how I could rectify this problem. Thankyou.