mack

iTrader: (2)

Have zero compression on cylinder #3. How can I determine if it's valve seats or rings causeing this problem. Motor only has 33,000 miles on it and of course it's out of warranty.

9formula4

iTrader: (5)

pull the head on that side and check your valve movement in the seat. Look in the cylinders to see if there are scratches in them or maybe piston movement. I would be more help for you but right now I just got off owrk from 11 pm to now.

mack

iTrader: (2)

I'm no mechanic, but I bought a GM 3 volume tech manual set and I've been doing a lot of reading. I think the first thing I'll do is pull the valve cover and check the RR and spring for that cylinder. If that looks okay, in comparison to the others, I'll see if pulling the heads is something I can handle. I don't think taking it apart will be a problem, it would be challenging to put it all back together adjusted properly is where I lack confidence. Maybe I should just return the new cam, rr, springs, retainers and keepers that I just bought and pull the heads and send them to LLoyd Elliot or someone like that. Then all I'd have to do is bolt them on and attach intake and figure out how to install the cam.

Formula350

iTrader: (3)

Well you could find someone with a fibre optic camera, like what Swat and Doctors use to peek into small places. Then pull the spark plug and take a gander inside. See if the piston has a hole or what not. Sounds like it's a stuck valve or a melted piston.

I'd take the air hose and put it in the spark plug hole and blow air through, then see where it sounds like it's coming from. If you pull the air duct off the throttle body, open the blades up and hear or feel air, then it'd be an intake valve open. If you hear it out the exhaust, exhaust valve, and if you don't hear either but sounds like it's coming from the crank case (maybe put your ear to the dip stick tube? lol) it is piston related. It's a cheesy idea I know, but I just made it up LOL It's something easy and I'd give it a whirl personally. Saves pulling a head!

Razor_Blade

iTrader: (8)

Not a bad Idea. It might work. He would need to back off the rockers for that cylinder, to make sure there were no valves open while testing.

Odds are the head will be coming off anyway.

mack

iTrader: (2)

Interestimg idea. Wonder if the air in the cylinder idea would work? I do have a compressor.

Formula350

iTrader: (3)

Oh right, yea forgot about having to pull the valve cover and loosening the rockers, which is still an easier job than a head heh Loosening the rockers alone might reveal a stuck valve! However, if the valve got stuck it's a good chance the piston slaped it quick nicely, and bend it, which yea the heads coming off :\

mack

iTrader: (2)

So what goes wrong to allow a piston to hit a valve? Sorry if this is an elementary question, but I don't know and I'm trying to understand how this happens.