I gota d16z6 130xxx miles stock, I got this rattle/tap/knock noise coming from timing side of motor, i checked for loose bolts, Motor mounts are tight along with everything else, I notice timing belt was a little loose so I tightend it up, I had the power steering and alternator off so I started it to see if maybe the bearings were bad and the noise is still there!!!, I stuck my ear on the bottom of the oil pan while it was runnin I couldn't hear a knock in there, drained oil and no metal shavings anywhere, I'm almost stumped, it idles fine, runs down the road fine, sound is mostly noticeable on idle it's an intermittent sound it's there and gone there and gone there and gone, when I rev it up it seems to go away I can faintly hear it, could it be water pump??? I'm clueless the only thing I can do is drive it until something gives, I'm hoping the techs can help me some

 

check is ur a/c barecket is missing any bolts cuz that cause a nasty sound

 

I think the a/c bracket is still there, but I can check, but it sounds more like down we're the timing belt is

 

PROBLEM SOLVED: turns out it was the water pump bearing, replaced water pump and noise is gone, timing belt I think was to tight, so far I got it so the timing belt doesn't whine so hopefully I should be set

 

FYI when posting questions that involve noises. Post a video if your able to. Glad you figured it out though.