Help figure out what knocking noise is
05-04-2013, 10:20 AM
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Help figure out what knocking noise is My LS-1 developed a knock after a short ride the other night, trying to figure out what it is? I shut it down & let it cool off, it doesn't do it when it's cold, I held it at a steady speed & pulled plug wires off & the knock didn't change by killing any of the cylinders. I also pulled the both valve covers & there wasn't anything visibly loose or broken. I'm thinking along the lines of a collapsed lifter, does anyone know how to tell if a lifter is collapsed or how to isolate which one it might be? It's got about 1500 miles on it since I put a crankshaft & bearings in it last year. Spun a rod bearing last year & it doesn't sound like that. Thanks in advance for any help!
05-04-2013, 04:10 PM
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It is steady with engine rpm, I dropped the oil as soon as it happened & there was very minor shavings on the magnet. But nothing different from previous oil changes since the rebuild.I just took a video, trying to figure out how to upload it.
Last edited by tommy396; 05-04-2013 at 05:14 PM.
05-05-2013, 09:11 AM
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If ya changed your oil filter cut the old one open. That will tell ya pretty much if its a bearing or not. I had a nasty knock in my truck about 300 miles after I built it and here my converter came loose from my flex plate. After I put on lt headers my truck sounded like it was knocking more but I just chalked that up to the thin headers.
05-11-2013, 05:54 PM
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I found a spun rod bearing....ugh! #5 cylinder. I just put a new crank and rods in it last year. With 1200 miles it spun the same exact bearing. Anyone know what might cause this? In any case, gonna build a stroker from TSP. Not sure if it will be a 383 or a 408. Depends if I can find an iron block quick n cheap. My t bucket only weighs 2000 lbs so not sure if I even need the extra power of the 408.
05-11-2013, 08:26 PM
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Yeah 89, that was a really good call!! I appreciate the tip, I cut it apart n found metal, that's what made me take the oil pan off. It spun the same exact bearing that it did last year (#5) . I put a new crank, two rods & all new bearings in it. Any thought on why it spun the same one? I even put a high volume & high pressure pump in it.