lunking sound

[robbigz]

Just after starting my Duramax 2500 HD I get a single lunking sound and feel. Note I have yet to move out of park. Usually it does it after the truck has sat. I'd appreciate any opinions...

 

P.S. I can't imagine its the dreaded slip yoke Robert

[GM-Tech]

Define"Lunking". Never heard that word before.

[robbigz]

Define"Lunking".  Never heard that word before.

 

<{POST_SNAPBACK}>

 

 

Basically a single bump sound and feel from engine area. Does not do it all the time... Just after starting the engine

Robbigz