I have an 87 900 turbo and had a guy checking it our today, he said the turbo wasn't working! The car runs fine (the boost gauge is inop) and accelerates great from 3k on up. What are the tale-tell signs that the turbo is out?

 

OH, you will know!! If you turbo in not working you will not have that large power increase at 3K rpm's. And if it is seized you will have a large bogging down of power on accelleration. Most likely your vacuum hose to the turbo guage has become loose or broken. I would bet that your "guy" saw that the guage was not working and assumed that, that ment the turbo was not either. Good Luck.

 

On exceleration you can still hear the turbo screaming then it's working fine. like IGUANA says check the vacuum hose.