When the engine is cold and I start the car I get a noise like a jet engine. Metal rubbing against metal. This lasts for about 45 seconds then stops. GM dealer replaced the air pump and fixed problem. Is this a common problem with a 2001 DeVille? Vehicle only has 8000 miles. Doesn't seem like that should fail at that mileage.

2 answers
Sometimes the age plays a part too, especially with a part like this. This pump will operate only when the engine is started cold (for a minute or so), and the amount you drive after that is irrelevant. So with this part, it may actually be worse to take a lot of short drives, which is often the case with low mileage vehicles.
I've seen many of these pumps fail, and I would make sure that the air pump check valve is OK. This valve prevents exhaust gases from getting to the pump and damaging it, so I would ask the shop if they checked that part for proper operation.
common problem with these cars but usually fail due to water damage because of a missing splash sheild driverside front of car