A few miles after the initial start up of the 383 in my '95 camaro, I started getting an engine knock. I've been chasing this noise since Thursday and still dont know exactly where it's coming from. I've even gone through some old threads over the last few days and checked some of the possibilities with a stethoscope. I decided to go ahead and make a post and hope to get a few other opinions.

It doesn't show up right away on cold startup, it takes a minute and then just doesn't go away. The noise does seem to get drowned out when I rev the engine, because I can't hear it if I'm outside the car. Although when I'm driving I can hear a ticking increase with the rpm's.

Here's the videos:
Above Engine
Below Engine

I've stuck my ear right up to the oil pan sump and can't hear or feel anything other than the hum of the oil pump. I've put the stethoscope against the front of the oil pan and can't hear the knock through the ear peices. I've checked the water pump & opti spark. I've checked around all the possible areas for exhaust leaks and didn't hear anything. I've also pulled the converter loose from the flywheel and started it up, but the snout on the converter is still slightly in the crank, so that creates another noise. I've checked the flywheel bolts and looked for cracks. The converter bolts were tight. I had a small amount of metal shavings in the oil after 5 minutes of run time, but after the 2nd oil change with 30 miles on the engine, the oil was totally clean. The oil pressure is at 60psi @ 2,000rpm, about 25psi @ 750rpm and 35-40psi @ 1200-1500rpm. I also bent the windage tray a little in order to clear the rods, I had about 1/8-1/4" clearance between the tray and rods.

The only place where I can put the stethoscope probe and hear anything resembling a noise is the passenger side freeze plug and even then it's a very faint noise.

If it's a wrist pin or piston slap, is there anyway to verify this? I'm using SRP Forged pistons and floating pins w/ scat h-beam rods.

I'm taking it to a friends shop after work and hopefully we can get it on a lift, if we don't get a definite idea of what that noise is, I'm pulling the pan just for peice of mind.

Any other ideas what I could check or something I missed? Can a rod/main bearing still be knocking without showering the oil with metal?

Thanks

 

on my 383 I had 3 problem areas with where the rods would hit. One was the windage tray
Two was the bottom of the pan up front, I think it was rod 1 and 2 and the last was rod 8 by the oil filter.