A common issue with the 5.3 engine is AFM lifter failure. In this video, we diagnose the problem and replace the failed AFM lifter and pushrod to get the engine running properly again. Follow along ...

We discovered that number 4 lifter on the AFM has collapsed. I have had the heads cleaned resurfaced and tested. No problems. I have ordered a AFM delete cam kit and a programmer. AFM is going away… ...