High Pitched Whistle After LZ0 Engine Replacement. Anyone Seen This?

[johnjohn722]

Hey everyone,

Looking for some input before I take my truck back to the dealer again.

I’ve got a 2024 Silverado ZR2 with the LZ0 Duramax. A few months back I had a minor oil leak that somehow turned into a full engine replacement. The truck ended up at the dealership for over 3 months while they worked through everything. When I first got the truck back, everything ran perfectly normal with no unusual noises. Both before and after the engine swap, I would hear the normal turbo sounds under load. I’ve had it back for about 2 weeks now, and a few days ago I started noticing a new issue. There’s a high pitched whistling noise coming from the passenger side of the engine bay. It happens when I’m cruising under light/steady load around ~1300 RPM.

Now instead of the normal turbo sound, it’s more of a steady whistle. If I let off the pedal or accelerate harder, the noise goes away. It only seems to happen under that constant load condition. Truck is completely stock aside from a drop-in K&N filter. At this point I’m trying to avoid dropping it back off at the dealer for another extended stay if it’s something simple. Curious if anyone here has experienced something similar, especially after engine work on the LZ0.

A few things I’m considering:

Loose charge pipe / possible boost leak
Intake or intercooler connection not fully seated
Vacuum line issue
Something related to turbo plumbing

Appreciate any insight or things I should check before going down the dealership route again.

 

[AXE]

Hey everyone,

Looking for some input before I take my truck back to the dealer again.

I’ve got a 2024 Silverado ZR2 with the LZ0 Duramax. A few months back I had a minor oil leak that somehow turned into a full engine replacement. The truck ended up at the dealership for over 3 months while they worked through everything. When I first got the truck back, everything ran perfectly normal with no unusual noises. Both before and after the engine swap, I would hear the normal turbo sounds under load. I’ve had it back for about 2 weeks now, and a few days ago I started noticing a new issue. There’s a high pitched whistling noise coming from the passenger side of the engine bay. It happens when I’m cruising under light/steady load around ~1300 RPM.

Now instead of the normal turbo sound, it’s more of a steady whistle. If I let off the pedal or accelerate harder, the noise goes away. It only seems to happen under that constant load condition. Truck is completely stock aside from a drop-in K&N filter. At this point I’m trying to avoid dropping it back off at the dealer for another extended stay if it’s something simple. Curious if anyone here has experienced something similar, especially after engine work on the LZ0.

A few things I’m considering:

Loose charge pipe / possible boost leak
Intake or intercooler connection not fully seated
Vacuum line issue
Something related to turbo plumbing

Appreciate any insight or things I should check before going down the dealership route again.

I think it's probably a loose hose or clamp off the turbo. I would take it back to them and tell them you want a quick look and fix right when you get there. This shouldn't take 1 or 2 hours and you should be able to wait.