94HotlantaTA

I bought a 94 TA from a guy cheap because the engine was knocking. I took off the valve covers and cranked the motor and all of the rocker arms, springs, and push rods look good. I did the plug wire test and took off the plug wire from every cylinder, but the knocking never stopped. Does anybody know what could be the problem??? It sounds like it's coming from the passenger side at the back of the motor. Not sure what to check next...

The Reapar

iTrader: (1)

Was the motor ever re-built?

94HotlantaTA

He had a receipt for a head gasket set and some miscelaneous small parts, but no major components plus labor at a shop done at around 150K and the motor now has over 210K

myltwon

iTrader: (1)

did you check the lifters? are all the pushrods straight?

94HotlantaTA

I didn't check the lifters, and I bought new pushrods because they weren't perfectly straight. Would the lifters still knock if I unplugged the spark plug wire from the cylinder?

the_merv

iTrader: (88)

Betya it might be a Bearing..how good is the Oil Pressure, and how loud is the knock..

94HotlantaTA

Oil pressure is above 40 and hits just above 60 when i give it some... The knock is loud enough to hear sitting behind the wheel over the flowmaster mufflers (not my choice i know they suck!) and it's quite loud when you are under the hood.

dre2013

iTrader: (7)

try to maybe use a stethoscope, and put it on the oil pan to see if the noise is coming from there? could be a loose/broken flywheel bolt, etc..hope u didnt spin a rod bearing

the_merv

iTrader: (88)

Sounds like a Bearing..

myltwon

iTrader: (1)

oil pressure sounds pretty good for a spun bearing imo

you sure it's not an exhaust leak?

94HotlantaTA

heard exhaust leaks before and its not the same sputtering noise you get from an exhaust leak. or at least it doesnt sound like it. too loud and borderline "violent" to be an exhaust leak. guess lifters are next on the to do list...

the_merv

iTrader: (88)

There is a difference in a "tick" and a "knock".
When my Stroker spun a Bearing, Oil Pressure was 60 at Idle, and it went up no problem when you revved it..it was piston slapping a little bit, that is how I determined it was a Bearing. That was a loud "tick", didn't even sound like a Bearing, but it was. I have never seen that before but it gave me a different look on things.

94HotlantaTA

Ok, well this is the first engine i've ever torn into, so I'm not sure what a spun bearing is. Also how much effort would it take to fix. I can turn wrenches all day long, i just need to know what's up.

myltwon

iTrader: (1)

here's a spun bearing clip on an ls1

http://www.n2s1.net/RacingVideos/havoc_enginesound.wmv

the_merv

iTrader: (88)

Yup..that's a Spun Bearing. Mine didn't even sound like that..just a sparratic tick from Piston Slap. Then again when you have a Forged Engine, **** tends to sound different and hold together..

ihaterice

your either looking at a spun rod or main bearing, or piston slap. what oil are you running also? if the oil weight is too high the lifters may not fill with oil causing a knock too. sounds like what happened with my car, it ended up being a spun main bearing!

94HotlantaTA

I'm not sure what oil he put in it last... I'm gonna change it and put Castrol GTX 10W-30 in it. And about that video, the sound that mine's making is not that much of a squealing sound it is more of a metal on metal knock. Another thing I found last night is that my exhaust manifolds are missing a couple bolts and they are rusted to hell and some of the other bolts were loose. Can you run the car with open heads? I know its probably not the best for it, but it will just be temporary to see if the knock is still there.

Also what is piston slap and would it happen without spark going to the cylinder, because i've disconnected every plug wire, and the knocking never stopped?

the_merv

iTrader: (88)

Sounds like a Bearing..

When you change the Oil, let us know if there it metal in it.

ihaterice

piston slap is when the piston has too much room to move in the cylinder and slaps the cylinder wall. it is not related to spark.

94HotlantaTA

Ok I changed the oil, and there were no visible metal pieces in it. I even dragged a magnet along the bottom and nothing stuck. Not sure if that rules out a bearing or not...