gagliano7

He already pulled the belt and the noise was still there.

Chris Bauer

I plan on pulling the covers this weekend and checking out the tops of the heads. Need to order a gasket kit before I pull the heads and see if a lifter spun or is flat spotted or seized up. I don't want to order new lifters if I only need 1 or 2 and a tray or 2. May just order all 16 lifters and new trays and just do it anyways.

00pooterSS

iTrader: (40)

Be best to do them all while there though especially since it takes so much work to get to them. Surely if one is on its way out others may be close behind.

G Atsma

And here is where you check all pushrods for straightness too. Just roll them on a glass pane or other VERY flat surface.
You might also think about a rocker bushing upgrade. The needle bearings (you will notice pivot ***** are not used here; that is Gen I-II small-block tech) in the rocker arms are not caged, and can find themselves where they should not be. Search these forums about this.

neblackshirts

So did you end up tearing into any of it this weekend? Curious as to what you may have found out.

kingtal0n

iTrader: (1)

The first thing you do with an unknown engine history is monitor the fluids, compression test, and pressure tests, followed by routine maintenance (pcv/oil/air stuff).

If the engine was ever "rebuilt" or "gone into" that is a rather large warning sign that signals you might want to start thinking of getting a backup engine and preparing yourself for the event that the current engine is unsalvagable due to internal injuries (metal flakes rampant). To open the engine is to invite disaster unless you are absolutely critical and clean, as in surgery, which I am sure you seem capable of from the way you type, yet the previous owner may not have been. Something as small as a fingerprint or hair can alter parts wear in some applications, and the lifter/cam/valvetrain of an LS engine is perhaps the most delicate balance of parts I have ever "seen" in something that apparently achieves 200k or more sometimes (often the untouched engines). It seems to be easy to explode tiny lifter rollers all over the place, or rocker needles. People using too much lift/spring pressure I think.


As to your noise, it almost sounds like something metal turning rubbing, like the camshaft's gear is rubbing against it's thrust surface. Inspect the oil for signs of rubbing metal/flakes.

neblackshirts

So what did you find out?

Chris Bauer

I haven't had a chance to pull it apart yet. I'm going to be staying after work today to check preload, rockers and pushrods. While the cover is off I plan to check and see if I have a collapsed lifter as well. It has developed a tapping sound under acceleration (top end) almost like a rocker bolt has worked its way loose or something.