| My Z sits 99% of the year. I have put maybe 3-4K miles on the car since the engine rebuild ~6 years ago. I change the oil every spring and put a few 100 miles on it before putting it back into winter storage. Sad life, I know, but its temporary. Or so I tell myself. A tune, new tires and this lifter noise is really all that keeps me driving it more. This past weekend I started my Z and let it idle to warm up. It had the normal lifter tick it always has had since rebuild, and as the car warms up it improves and smooths out. Cold idle around ~1700RPM and then settles in around ~900RPM once warmed up. Once the idle settled down I noticed the lifter tick was still fairly audible, and gave the engine some finger throttle (push on the linkage "cam" by hand) to bring it up to 3-4k RPM for a few seconds. Normally a few revs into higher RPM then idle the lifter tick will smooth out if its hasn't already just from idling. This time when I came off throttle and RPM dropped from ~4k down to ~900RPM there was a louder sound from the PS bank. A rattley clanky sound is the best way to describe it. I am not sure what to make of it or how to safely proceed trying to diagnose. I don't want to risk damage to the engine by continuing to run it in an effort to narrow down the culprit. Valve spring? Timing belt losing tension on decel? Lifter related? I made this video 5 years ago, and while its hard to capture engine sounds clearly, the video is still relevant to what I am hearing now - just louder. Its the quick chattery sound when I let off the throttle and the engine speed slows down. https://youtu.be/7CKcTu4HFhw
Jared
1994 Twin Turbo |
