Ramdriver15

well i fired up the truck and drove home from my friends house who lives literally a 45 second walk away but we went out to the store and went there after (im not lazy... ) But any way, i got in fired it up and drove home. The whole trip the turbo was humming, like normally its a whistle but this time it was a bit deeper like a bearing noise... does this mean i am over spooling my turbo and need to back off a bit to extend its life? I am making 40 psi of boost at peak, and average about 20 psi around town. Also is it because the truck was cold or am i just hearing things... lol

Teddy Bear

40 psi is not too much for your turbo. Are you sure the fan wasnt on? Those fans can be pretty noisy sometimes when you have the a/c on.

plow

I think mine does the same thing, its starts off whisling pretty good then around 38 psi it stops and starts humming like you said still pulls good no power loss just a sound change. I would think it is caused by overspool being that 36psi is about max on the stocker.

Ramdriver15

well i wasnt making that muh boost at the time, i was probly runnning like 6 psi at the moment i was hearing this noise while i was idling up my street. I was making quite a bit of noise earlier that day then the truck sat for about 2 hours and i fired it up and heard the humm.... but i went out this mornig and started it up and let it idle and no noise yet but i guess we'll find out when i go to the beach today. ill post back with what i hear.
thanks a bunch,
John