[fogster]

Upon accelerating hard in D5 (mine is a 2003 V70), you find that the car's power suddenly stops pulling around 2-3000 rpm, with the car very reluctant to climb above that (mine was accompanied by the sound of someone trying to such an orange through a hosepipe!). However, when accelerating gently, the car pulls cleanly all the way to the red line. The collapse was accompanied by the "Engine Service Required" warning which cleared upon an engine restart.

The problem was not the intercooler, turbo or anything other expensive - it was the turbo inlet pipe. It had gone soft with age and had split; when accelerating hard the pipe was collapsing, starving the turbo of air. Accelerating gently meant the pressure was never enough to collapse the pipe. The pipe is only about £50 and a relatively easy fix - on my car, I could actually see the split before asking my local garage to swap it whilst in for a service (they only charged me for 30 minutes labour to do the job as they were doing the cambelt at the same time) - and that's my Volvo main dealer (Johnson's of Swindon).

I've written up the location on the attachment as the pipe is a little awkward to find but easy once you know where it is. I'd guess you could easily do this yourself (I was being lazy as the car was going in anyway).

Hope this helps!