Hello, Wifes 07 suburban (5.3 AFM ) started making an engine noise ( knocking sound) while on vacation. Pulled in to mechanic since there was no Chevy dealers around. He stated immediately that is a lifter and cam problem. He also asked if it has been using oil and I said I have noticed it uses about 2qts every 3000 miles between changes. He stated that is bad. After I got back I researched it and it seems to be a common problem for 07's. The burb has 101200 miles on it ( my bad luck just out of warranty). My question is should I have a cam and lifters installed for around $2000 or should I get a newer junk yard engine for a little more with low miles and put it in. I am concerned about all the oil it used over the years carboning up the piston and rings. I know it can be decarbed but there might already be wall scarring. Can a non afm cam and lifters be put in and then deactivate the afm? Any advise on where to go from here would be greatly appreciated.