ss1129

iTrader: (16)

I missed a 3-4 shift. Well it sounds like bent pushrod syndrome. Check all the pushrods.....notta. Scanned it with a snap-on scanner.....hella misfires. Then when I started my compression checks. I started at #2 about 125 then #4 about 125....then #6 (misfire cylinder #1) 0 psi. So yeah the piston isnt moving anymore. Then for ***** I checked #5 (misfire #2) and again 0 psi. So did the crank break or did the connecting rods fail?

Well anyway Im looking for a cheap replacement for it. Will any 6.0 iron block from the suburbans and escalades fit? I see them all over ebay for cheap. I figure get a short block and buy some decent heads and cam, and I will be good to go. Or am I stupid for thinking that its that simple?

LS1 Sounds

iTrader: (11)

Could also be bent/broken valves, have you already checked them?

ss1129

iTrader: (16)

Only on the passenger side. I kinda of just stopped checking for things after I found 2 pistons werent moving anymore.

Beast96Z

iTrader: (21)

0 pressure dosen't mean the piston isn't moving. Like LS1 sounds said, if there is a bent valve/valves, it will release all your pressure. It's always best to open the intake and exaust and listen if you can here the air coming from either. Air coming in the intake will be the intake valves, air out the exaust wil be exaust valves.

LS1 Sounds

iTrader: (11)

Were you actually looking at the pistons, watching them stay still as you rotated the engine? Your description makes it sound like you are basing your diagnosis on the lack of compression.

jermstyle

I think you would be able to tell if you had 1 or more pistons not moving with the others. Sounds like a valve issue.

jRaskell

iTrader: (1)

I really don't think there'd be any doubt at all that you broke a rod/rods or the crank, without even diagnosing it. More likely bent valves that are preventing it from building pressure. Best to just take the heads off. You already know it's serious enough to remove the heads. That way you can see exactly what the damage is, and then check for any piston damage as well.

DaddySS

If the pistons weren't moving (broken rod) you'd know it from the unblievable noise and probable siezure of the motor. Sounds like you bent some valves and if you're lucky that's all. Pull the heads and go from there.

xaon

iTrader: (12)

I'm with everyone else... if it were broken rods, you WOULD know it (there would likely be a hole in the side of your block)

My diagnosis would be bent valves also.

SHINER

iTrader: (18)

I said its a BENT VALVE..Hand Down, makes total sense for the escaping pressue equally no compression. If you threw a rod you would DEF. notice it alot more than your symptoms...Just for giggles how did u miss a 3rd to 4th gear Shift?

35th SS

iTrader: (2)

prolly slammed it back to 2nd instead to 4th.just guessing.

ss1129

iTrader: (16)

I dont think I went into second. Thats the thing, is that nothing violent really happened to the motor. I went from 3rd and tried for 4th, but I think the clutch line boiled over and wouldnt let it in gear and my foot reacted faster than my hand and it bounced off the rev limiter (factory set still) once or twice. Well stuck a pen in the plug hole and cranked the motor and nothing happend to the pen. Thats where the assumption of broken rod comes from. But I will take your advice and remove the heads first. Thanks guys.

Rebelord

iTrader: (2)

If you broke a rod, like everyone has said. You will know, probally wouldnt have been able to drive home after that. Pull the heads and go from there.

Ski

Raise

iTrader: (31)

if u put a pen in the plug hole and didnt feel the piston pinch it, then something is wrong. u sure u turned the motor over enough to lift that piston?

jrc316

Could have broken the cam also, this could account for the 0 pressure as you move back on the engine... Russ

GuitsBoy

iTrader: (4)

Almost 100% certainty thats its bent valves. You probably got lucky and only bent the valves, cause if you broke one off, youd almost certainly know it, and the motor probably wouldnt crank. Dont run the motor anymore. Just pull the heads. might be a good time to invest in some new heads, and maybe a cam. You can get ls6 CNC ported heads and valvesprings for liek 1150 or so, then another 350 for a cam, and 100-200 for misc gaskets and what not. If youve gotta buy parts anyway, might as well upgrade while youve gotta do the labor...

1BADAIR

iTrader: (1)

Sounds like valves.
if you had upgraded pushrods with out springs its definately bent valves.

Doomsday

iTrader: (8)

Damn that sucks, NOT very cool dude. Now your going to be paying for it like me.

xaon

iTrader: (12)

you can also help diagnose it by using an air-hold adapter (like you would use for changing valve springs). Hook up the air and then put your ear up to the exhaust and the intake, you should be able to hear the air out of one (or possibly both) if it's a bent valve. I know air was screaming in my intake when I tweaked one of my intake valves.

Raise

iTrader: (31)

what hes talking about is called a valve holder. its a fitting for an air compressor for changing springs. if u hear it coming out of the intake then its a bent intake valve. if its coming out of the exhaut ports, then its a bent exhaust valve. you can get it at pep boys for 10 bucks.