I've got this tick/rattle noise in my engine. It sounds like lifters but I've been told that if it's lifters the sound will get worse when the engine is hot. My noise usually goes away when hot, not always. Yesterday it was making the noise and while revving the engine myself & some co-workers determined it to be coming from the front cylinder on the driver's side. I let the car sit for like 3 hours started it back up & no noise. This morning it was really noisy until the engine was hot, then quiet. When it is making the noise it seems like a ping when I'm in 6th gear with like 1600 rpm any time you give it gas. I haven't logged any misfires either, even if it's making noise my power seems normal. I would like this noise gone, but my wife wants me to just drive it. I told her if I hurt the motor it's going to be like $6000 for a shortblock, lifters & cam. Of course she didn't say anything more, but I would rather just spend money on a couple of lifters or maybe springs if that's the problem. I can't seem to narrow it down. I put in a used cam, new ls7 lifters about 1000 miles ago. I did also have oil pressure problems the first few drives. Any thoughts what this could be & why is it itermittent??