Clicking sound when trucks off but I’m still in it

[ILSilverado]

On 7/9/2020 at 6:08 PM, Wayne Black said:

You should hear the sounds my 3.0 Duramax makes when it is shut off.

"Clack, clack, clack, clack, weeeze!".

Seems there is a valve that sends water to various parts of the engine and passenger compartment at different temps when cooling/heating.

After the engine is shut down the valve cycles through several positions for some reason.

Exactly it sounds like a Donky wheesing