Pontiac Repair: lifter knock, pontiac grand am, compression test

Question
1998 Pontiac Grand Am 3.1 SFI V6 Sounds like #6 Lifter is collapased. Code P0306 Comes out when you reset computer. How hard is it to change lifters and cam or do you think this is the problem. Also changed the coil packs. Plugs look like they are firing good

Answer
Hi Aaron:

A p0306 is a misfire for cylinder #6. it could be a bad lifter and the cylinder is down on compression due to that. It could be a broken valve spring causing the noise and loss of compression. You could have a lean injector causing the issue. Changing the lifters is not that big of a job but changing a camshaft on that engine is. The cams usually on those engine do not wear out but on occasions lifters do. More than likely the noise you hear is coming from one or both on them from that #6 cylinder. I would do a compression test on the engine first and for most and then go from there.