I have an 89 yj w/ a 258. I recently replaced the hydraulic lifters and the rocker arm assembly but kept the original push rods. I replaced the lifters because I was getting a ticking noise during warm-up and occasionally during idle(disappears the moment I raise the engine speed). I don't get that noise anymore however I'm getting a different kind of ticking noise. The NEW noise comes on after about two minutes of driving and during acceleration, the moment I ease on the gas pedal the noise disappears. I don't get the noise when downshifting. When I rev the engine quickly, I could hear it a little bit. also the acceleration is great when the noise is not there, but it gets worse as the ticking starts to appear. The noise progressively gets louder. If I shut down the engine for about five minutes and then restart, the noise would disappear and then come back again after about two minutes.
Someone told me that it might be spark knock so here's what I did...
I switched to 92 octane
I decarbonized the combustion chamber with MOPAR combustion chamber cleaner
I adjusted the timing
I checked the EGR...its ok
I retorqued the manifold bolts...found one bolt loose
I'm not really sure if it's spark knock anymore...I don't even know exactly what spark knock sounds like
I need some advice...HELP!!!