Long story short - I bottomed out going 75 MPH down the freeway and the truck went into reduced power mode and acted like it was in neutral. Had it towed home and through a series of diagnosing I found the timing chain had jumped off the cam sprocket. Since I was in there I opted to replace both sprockets, the tensioner and chain and now the truck starts but is running very rough and throwing a P0016 Crankshaft to Camshaft position Correlation. Upon further inspection, even though Amazon said the VVT cam sprocket I bought ("VTG3216", same as a typical 6.0L GMC) was compatible with the 2011 Yukon Hybrid, the TDC timing mark on the cam sprocket is about 20 degrees offset compared to the sensor tabs that hang off the original sprocket.

Needless to say I need to take the oilpan and front cover back off and swap in the correct sprocket...just want to confirm and share here that the correct GM PN for the cam sprocket is 12602699 and NOT 12606358.

Anyone else here have experience with changing the cam sprocket and can confirm my findings? Planning to tear back into it tonight, but it is what it is.

 

I'm been working up to changing oil. pan gasket. seeing yours I kind want ti replace the chain and tensioner too.

got a 2k mile tow coming up in Sept with 170k on it. don't think I'll get to it before. fingers crossed