db057

I have a 92 Camaro rs TBI 305. I recently got this Camaro a month ago (never had so many problems up front), but here is another and I've noticed it for a while. there is a hard knocking that you can feel with the engine idling or revving around the 6th cylinder on the back left side where the breather pipe goes comes out of the valve cover into the filter on the cleaner housing. Listening with a scope, it is around the 6th cylinder. I've tried to readjust the valves in that area and it didn't get rid of it. You can feel it with your hand when you touch the pipe or cleaner housing and kind of hear it out of the exhaust or maybe its loud enough you can just hear the thump rhythm. When revving the engine with the scope on it to listen, sounds like a flutter. I can't really word it right but I can sound it out if I was verbally saying what it sounds like. You hear the knock-knock-knock and then it's a flutter sound when you rev it then goes back to the knock. Besides an engine repair in the future, is there anything else I can look at that can cause the problem, especially in the back 6th cylinder. I have replaced the dist. cap/rotor and a bad ignition module/pick up coil. plus new spark plugs but it's isolated to that one cylinder, because everywhere else sounds good. engine doesn't misfire or backfire, oil pressure is good. can idle/vibrate a little on idle. maybe a small hesitation on acceleration but also the exhaust is loud, so maybe just a little bit of lost power then kicks up and moves really fast. You can hear it a little bit, like I was saying possibly through the exhaust or maybe through the air housing/pipe, but otherwise you really hear it when you have a scope and touch around the area.

TylerSteez

iTrader: (3)

Does the car have headers or the stock exhaust manifold? A leak at where the header/manifold meets the head can sound like a knock or a bad lifter. If you have headers try tightening the bolts, if you have an exhaust manifold then it'll be a huge pain to fix.

db057

it has the stock exhaust manifold. the exhaust is loud in the back muffler area already and you can kind of hear the rhythm of the knocking through it. You can also feel it by putting your hand on the area where the pipe comes out of the valve cover that goes up into the breather filter and you can feel the knock also if you touch the air housing cleaner . from the other side of the car even. It feels like someone it taking a hammer and punch the valve cover from the inside. otherwise , it doesn't idle/drive too bad

db057

It also does still idle a little too high for what I am used to (or my old Camaro which was the same year/engine did). when I first cranked it was at 30 rpms, then worked its way down to 20

db057

Resolved the Knocking issue!! It was my own fault, bent part of the inside of the valve cover when I put it back on the engine. Just a hard part to get up over the rocker arms with the engine in the car, so the rocker arms must have been banging up against it but now, the knocking is gone!! Yes!

Still idles a little too high and a little too rough, also noticed with the timing light now, it fluctuates just a bit.. when the timing on 0, pointer moves probably halfway toward the next marking then back... very slowly.