Whats the main problems With 07-13 silverado 1500s

[diyer2]

While I agree the AFM design has had issues, I disagree with saying stay away from them.

My bought used 2012 5.3L, 6 speed 3.42 runs very good IMO.

Transmission shifts great.

I took a trip yesterday here in the mountains of Colorado.

300 hundred miles, from 8 K feet to mountain pass over 10 K feet, long grade pulls, many elevation changes.

Put about 800 lbs. in the bed on the return trip, not a lot of weight I know.

Pull my 20 ft. boat to the lake under the same conditions.

Have towed over 8 K pounds in high country.

Will it keep up with a 6.0, 6.2 L or a diesel, NO.

The truck does the job though.

NOT ALL 5.3's have issues though!

 

 

[Z45]

Active Fuel Managment (AFM) and poor quality control on parts that made through at the high end of their tolerance limits.  In others words, GM pushed AFM on customers and it was not engineered to the highest standards.   

 

Re:

This condition may be caused by oil spray that is discharged from the AFM pressure relief valve within the crankcase. Under most driving conditions and drive cycles, the discharged oil does not cause a problem. Under certain drive cycles (extended high engine speed operation), in combination with parts at the high end of their tolerance specification, the oil spray quantity may be more than usual, resulting in excessive deposit formation in the piston ring grooves, causing increased oil consumption.