buzzing noise under boost

[proclad]

Hi there new to the forum. I was told this is the place to go for an answer. So here goes.

From the drivers seat of my truck while driving. and under boost I hear this loud buzzing/bearing noise from behind the dash on the passenger side.. I can make play with the skinny pedal and make the noise loader or quieter. Doesnt do it at idle or cruzing, only once boost starts to build up and gets loader as the boost goes higher. I've taken it to the dealer 2 times. First time they said the right turbo shaft assembly was the problem so they changed it. picked the truck up and sure enough before i got 2 km from the dealership it did it again. So they booked it in again. 2nd time they told me there was a right side turbo issue and that they were just going to repace both turbos(not before grilling me because of my after market airfilter and dpf back Banks exhaust) Anyways they changed both turbos and today i picked up the truck and as i accelerated from the parking lot the noise was still present. So frustrated i do not know what to do. They have had my truck for a total of 7 days and its costing me alot to have my work truck down.

Does anyone have any ideas of what this could be. So i can at least bounce them of the mechanic at the dealer. The dealer has stepped up and replaced alot of $$$ worth of parts but i believe they have replaced the wrong things.

Thanks any help would be appreciated.

[dieselkane]

Sounds more like an exhaust leak to me. Look at the up-pipes leading to the turbos and see if you can find signs of soot. Either on the firewall, or on the flex joint itself.

[proclad]

Ok ill check it out. Do ya think that would be something the dealer would look at before replacing both turbos. Kind of crazy if it is infact the up pipe. So a leak in the pipe makes a squeeling/buzzying noise. I never would have though it. I sure hope this is it. Its driving me nuts. I want to get everything cleaned up before i do a DPF delete and tuner. Cause if their giving me a hard time with a filter and rear exhaust they will definately laugh at me with a tuner.

[sschefer]

It's just turbo fart, you never heard it with the stock air filter because it masks it. My 08 does it too. If it's like mine, when I've got my foot in it, it sounds like a waste gate blowing off between shifts. Actually, that's pretty close to what's happening.

When you shut it down does it sound like a box of marbles as the turbo spins down. Mine does, it's the K&N intake resonating. Sounds like a turbo going south which is probably what the dealer thought too. It's nothing but resonance noise and is typical on the twins from what I've discovered. No need to worry. Just relax and enjoy that sweet smooth accelleration you have now.