Low compression after cam install

[Dave Kiefer]

Need help. 2010 Yukon 5.3 flex fuel. I had a bad lifter on # 3 intake. Installed Melling cam and lifters, including AFM. New gm cam phaser and vvt control valve. Now have low compression on 2, 4 and 7, 150 psi on non AFM cylinders. Backed rocker arm bolts 3/4 turn and compression up to 150. Made sure timing marks lined up. Any thoughts are appreciated.

[Jsdirt]

Were the cam bearings good? These are notorious for walking out of their bores.

 

Another note - you MUST replace the VLOM when doing this job. If you didn't, you're going to have to tear the intake off again and replace it. This has burned many over the years.