I own a 2005 GMC sierra that developed an engine knock at idle

I had it checked out by 2 different shops and both tell me its an internal problem and said they couldn't say for sure what it is until they tore the engine apart

I haven't tried go to gm but i am going although i doubt they will do anything

In the meantime i am shopping for a used engine because i don't think this one will last

This will be the last gm i buy if they cant build an engine that goes bad at 50000 miles