lifter knock problem???

[LIL6cyl]

OK, I put on my new exaust today, it was sounding good and so I took a spin. I got on it, it ran like a champ. I pull in to my driveway and It was knocking. I was running 15 lbs of boost, I got 3 green lights on my knock gauge. I think a lifter colapased. I pulled my pass valve cover and one of the #2cyl valve is making noise, but there is a much deeper knock than that. The deep knock is in time with the noisey valve. can a bad lifter make that much noise?? There is NO metal in the oil. The Engine has 4000 miles on it. the knock comes and goes, Its not constant. Any ideas??

thanks
Bryan

 

[turbov6joe]

Didn't give enough info to be 100%, but it sounds like possibly a flat cam lobe....don't ask me how I know

 

[frankg]

You could have a bent pushrod also. Frank