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top end clanging

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Old Feb 7, 2012 | 08:07 PM
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Default top end clanging

earlier tonight i was leaving my cousins house then all of a sudden my car starting making a tapping noise, stumbling, and barely running. i creeped it into a neighbors driveway and shut it off.
i cranked it really quick and listened to the sound again and it sounds like a clanging metal to metal noise in the top end on the driver side. its idling very low and struggling. the clanging is very loud. i mean its barely running.
any ideas what that is? my first thought was that a valve spring broke and the valve dropped. but i think it would have been worse if that were the case? or it could be a lifter broken.
i am running comp 918s with a fairly big cam and i know they have been known to break. i hope my ls1 is not toast. im so pissed right now.
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Old Feb 7, 2012 | 09:24 PM
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havent had a chance to pull the valve covers yet, but i did check the oil its down 2 quarts. it may be spun rod bearing but it sounds like its in the top end. i know my rear main seal was leaking but i just checked the oil the other day and it was fine. could it the lifters are not pumped up all the way due to the low oil?

Last edited by FL Junkie; Feb 7, 2012 at 09:34 PM.
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Old Feb 8, 2012 | 07:56 AM
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take a long screw driver hold it to your ear and to the top of the motor while its running you may be able to pin point if its top end, worn or broken valve guides can cause a oil consumption issue?> how was your oil pressure?
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Old Feb 8, 2012 | 06:54 PM
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I'd pull the valve covers before running it anymore ... sounds major.
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Old Feb 8, 2012 | 10:30 PM
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ok i pulled the valve covers off today and it turns out one of my valve springs broke. the valve is still in place. the rocker, pushrod, and retainer are ok.
so what should i do next? i could put a spring back on it and attempt to crank it that way. or i could play it safe and pull the heads. i dont know if the valve is bent or if it hurt the piston. any advice?
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Old Feb 9, 2012 | 09:14 PM
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Originally Posted by FL Junkie
ok i pulled the valve covers off today and it turns out one of my valve springs broke. the valve is still in place. the rocker, pushrod, and retainer are ok.
so what should i do next? i could put a spring back on it and attempt to crank it that way. or i could play it safe and pull the heads. i dont know if the valve is bent or if it hurt the piston. any advice?
Step 1: Put that cyl on TDC, pull the broke spring and see if the valve moves freely. If not, pull it apart. If the valve "seems" OK, go to Step 2.
Step 2: Put a spring on it, make sure that cyl is on TDC, air it up and see if it leaks. If so, pull it apart. If not, start it.
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