I have an 04 max that lost compression in cyl 2, 4, and 6 because the rings got stuck in the pistons. I pulled the motor, sent the heads off to get cleaned up and the valve guide seals replaced. Put new pistons in and put the motor together and when i turned the car over there was a rhythmic metallic sound coming from the head for cyl 1, 3, and 5. Timing all looked good but i pulled the head to check for damage anyway and it all looks normal. I did notice thing that if i push the intake valves open and then let them close that they make a sound of metal on metal. The exhaust valves don't make any noise when they close. I'm wondering if there's something not adjusted right or if it's from a lack of oil pressure because it's basically a fresh rebuild. Any info would be appreciated. I'm petty decent at the actual work building the engine, but i don't know much about the heads other than the basics. Thanks again guys.

 

What oil are you using? What oil filter are you using?

For me, lifter noise with Pennzoil was quite loud, so I have gone back to using Mobil 1. It has lowered the noise considerably. As for oil filters, I flip flop back and forth between Nissan and Napa Gold.

The lifters should self adjust due to oil pressure.

You say you had some stuck piston rings. Hence, the rebuild. That tends to be an oil maintenance/extended idling issue. Some of your oil passages/journals may be restricted, so some long drives would help to clean out the pipes.