noise

Phantom 4D · January 6

When I shut down my 2023 Sierra 3.0 diesel, there's a noise coming from under the truck. I know it's funny, but it sounds like a small frog croaking. The tech at the dealer said it's the DEF return pump.

Loadmaster · January 6

Did it always do this or is it a new noise? Does it happen every time it is shutdown? What happens if you start it for just a few minutes and shutdown, does it still make the noise? Any codes?

gemarsh · January 6

Turbo vane actuator

Phantom 4D · January 9

On 1/6/2024 at 4:13 PM, gemarsh said:

Turbo vane actuator

From under the rear?

Phantom 4D · January 9

On 1/6/2024 at 3:53 PM, Loadmaster said:

Did it always do this or is it a new noise? Does it happen every time it is shutdown? What happens if you start it for just a few minutes and shutdown, does it still make the noise? Any codes?

It's always done it. Most times after running around town or say a 120 mile round trip. If I just start it and let it idle, shut it down, normally no noise. No codes. I'm thinking the GM tech is right. The DEF return pump.