Volvo Repair: turbo unit, turbo unit, son of a gun

Question
how do you know if the turbo unit is bad or if it has gone out, what would be some of the signs that the car would do, to let you know if is bad. thank you, vickie

Answer
  Vickie, usually there will be a lack of boost pressure. Other things can cause this also though. Leaks/tears in the pressre hoses, blown intercooler etc. Usually they will "howl" like a son of a gun if the bearings are going out. Unusual for one to fail though.

Mark