So i picked up an 02 on Thursday with obvious valve chatter and drove it 23 miles home and parked it. Yesterday I did the valve lash, ngk iridium plugs and fired it up to hear a more frightening noise now that valves are quiet, I suspect rod bearing but would like a second or third opinion.

History: car has 145k on it , bought from an insurance adjuster, a woman in her 50's that owned the car for the last 6 years(makes me think she probably didn't beat it but probably neglected it), oil change sticker says they put 5w30 in it, due at 146k or 2016, oil still looks nice and golden and is full (wasn't going to change until i did valve lash), carfax history shows wp and belts done. looking over the engine the tct looks like it's been replaced has ntn and the numbers etched on it are 011017 (build date or sn?). She claimed the noise started last month and she parked it, I believe here because i found dated receipts from the grocery store in it.

Maybe i'm over thinking it...idk

Videos:

 

Sorry mate but that sounds terminal to me...

 

oh, boy. That doesn't sound ideal.
darcy

 

In my experience rod knock is a bit more random and isn't so consistent (my AP1 spun a rod bearing). I had a more similar experience to your when I lost one of the valve adjustment lock nuts. Given that you're hearing this sound AFTER the valve adjustment I'm a bit compelled to say its related. Were the valves even out of spec? Could they be THAT loud that they would cover up such a noise.

Here is what I thought was "rod knock" but was the missing valve adjustment lock nut.

 

i'll pull the cover and recheck, i looked at the retainers, slid the feeler gauges under all but only touched the ones that were out of spec(1 and 4), I wasn't really paying attention to the lock nuts so I can't say for certain... worst case pull and replace bearings

 

That's not bearings, but you can easily tell by individually pulling a coil pack and seeing if the noise quiets down. When the offending cylinder no longer combusts it'll quiet the knock.

 

So it is a bit strange that it made no noise before the valve adjustment though? I wouldnt think valve chatter could cover that noise up.

 

Valve chatter could very well be the noise we're hearing. It sounds like this when the adjuster screw is backed off all the way.

 

I agree with slowcrash its worth going through and re checking your valve adjustment job first!

 

Just finished going through and triple checking each valve. Clearances are right and all lock nuts in tact. Disconnected each coil with no obvious change in noise. it still sounds more top end to me but idk