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symptoms of a collapsed lifter or bent valve?

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Old Sep 3, 2005 | 02:46 PM
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Default symptoms of a collapsed lifter or bent valve?

Well Im still misfiring on number 5 and& cylinders. So that leaves me to believe its either my lifters or the valves. What are some of the symptoms of each?
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Old Sep 3, 2005 | 04:37 PM
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- Loss of idle vacuum (drop in reading, and/or needle bounces if valve not sealing)

- Loss of compression

- Ticking sound if rod is bent beyond pre-load adjustment amount

- Eventually valve guide wear and oil into chamber with a bent valve stem

Have you pulled the plug to 'read' it? How about a comrpession check?

Further to that, pull the valve cover and remove the rocker and rod.
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Old Sep 3, 2005 | 04:47 PM
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yeah i did it all but the compression check. my only other idea is the lifers or the valves cause everything else has been replaced
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Old Sep 3, 2005 | 04:57 PM
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A compression test is probably your best bet at this point.

I wouldn't begin replacing parts until you can narrow down the cause.
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Old Sep 3, 2005 | 04:59 PM
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thanks. i just need to get a compression checker then. should i just compare those 2 cylinders to the other 2 on that side? i just dont get why this all of a sudden happened or if it was part of an old problem i was having.
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Old Sep 3, 2005 | 11:20 PM
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Compression or leak down will tell you if it is a valve. I just tried a leak down gauge for the first time. My 18000 mile LS1 motor that I sold was 2-3%, I was impressed. My new forged motor with JE pistons and rings is 4-5%. Probably more end gap on the rings cause it to leak more. Both were cold tests. Probably a good idea for you to look at spark plugs, valve springs, and pushrods.
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Old Sep 4, 2005 | 12:15 AM
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i have a similar problem( not trying to hyjack your thread) but had real loud top end knock aroung #2 and pulled valver cover and rockers and nothing was wrong so i pulled driverside cover and pulled rockers and all exhaust pushrods were bent to hell. The noise is a loud metal to metal ticking but i cant pin.point it cause i put in new pushrods and it still does it and none of the valves look to be sticking. ??????
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Old Sep 4, 2005 | 01:16 AM
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well im pretty sure thats its one of the 2. either way, the head has to come off. Im going to take the head in to the shop to get all the valves on those cylinders checked out as well as replace the lifters that i got.
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