Uh-Oh?! engine noise!

So here it is, engine seems to run okay, but around 3,000rpm I start hearing noise at the front of the engine. sounds higher up and is not a deep knock, but clattering. My guess is the timing chain is shot. Sound about right?

In my humble opinion, timing chain noise is typically noted at lower RPMs where the slack in the chain is greatest. As you speed up the motor, centrifigal force will tighten up the chain, unless it is to the point of hitting the cover.

You can get a wrist pin knock at high RPMs too.

Maybe a valve train issue? Weak spring, bent pushrod?

Check your valve train.

I would guess valve train, lifter or rocker issue.

I was hoping for the chain, but the valve train makes more sense-hopefully something simple. It does sound like it's coming from inside the front of the rocker cover. If I have the car idling and stick my head under the hood and bring up the rpm, it is definately noticable starting around 2800 rpm. I doubt a bent pushrod as I have the oversize ones-maybe one of the brass adjusters let go? Best case is it just needs an adjustment, but that sounds unlikely.

Try and locate it with the screwdriver stethoscope. Take your BHS - the 18"er - and put it here and there on the valve cover or the block. Lean your ear against it. I usually press that little bulge in the front of my ear, the one that covers the ear passage, on the butt of the handle. It transfers the sound right into your ear and you can tell if you are closer or farther away from the noise as you move it around.

I believe you need a different diagnostic technique for the timing chain cover. It's hard to get your head close to it with the fan running at 2800 rpm or more.

If you have adjustable rockers, it is possible one backed off. i had that problem for like a year. Every 2 months I had to readjust the rocker. Then all of a sudden it stopped backing off.