Sudden Turbo Whine?

[DAldous]

After towing my 5th wheel through 43 states, my 2000 cummins developed a loud turbo whine (or whistle)!



It happened very suddenly while climbing a mild grade (no trailer attached) in the California Sierras. My wife and I heard it at the instant it started. We turned to each other asking "what is that"?



I have inspected the air intake (pre-turbo) including the silencer ring and see no obvious problems. I have had a K&N air filter since the truck was new. The truck has 45,000 miles on the odometer. Performance has not degraded due to this new noise.



Any ideas or (even better) solutions?

 

[Tom W]

Did you check the snorkle? Also there is a piece of foam insulation in the back of the fender well that could have come out, it's right in front of the door.

 

[No Neck]

Check all the clamps and hoses on the high pressure side of the turbo. Chances are you are hearing a pressure leak.

 

[Floor It]

Tom W probably hit right on the money, mine too one day had the turbo whine get a little bit louder and I found that foam piece in the passenger fender turned side-ways and fallen down. Later on I liked the sound so much the turbo silencer ring fell out too!