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Old Oct 17, 2011 | 08:09 PM
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Default Engine knock

Hi I have a 68 454- drove it a few times this summer and the last time out it started knocking about a mile from the house. It knocks LOUD when idleing and faster when pressing on the accelerator.
Any idea what this might be and a possible fix without a mechanic?

Thanks!
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Old Oct 17, 2011 | 08:12 PM
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upper end or lower end?

upper end is a bad lifter, dropped valve etc,
lower is a rod knock and needs the short block rebuilt

You can start it take a stethoscope and listen around the engine
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Old Oct 17, 2011 | 08:19 PM
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As he says, try to locate the noise with a stethoscope. You can also, with the engine idling, pull off the spark plug wires one at at time (carefully, there's a lot of voltage there!). If the noise goes away or diminishes, that'll tell you which cylinder it is -- usually indicates a bad rod bearing.
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Old Oct 17, 2011 | 08:20 PM
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What do you mean by lower end or upper end. Sorry, I dont know much about the engine
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Old Oct 17, 2011 | 08:48 PM
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Originally Posted by Mel07
What do you mean by lower end or upper end. Sorry, I dont know much about the engine
Where do you hear the knock coming from?
Is it in the bottom part of the engine, or the top part?
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Old Oct 17, 2011 | 11:07 PM
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lower end is crank, rods, pistons,
upper end is heads, cam, lifters, all the valve train componets
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Old Oct 18, 2011 | 08:48 AM
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Originally Posted by Mel07
Sorry, I dont know much about the engine
Here's a fact: no 454's were produced before 1970.
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Old Oct 18, 2011 | 09:07 AM
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Is there oil in it?
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Old Oct 18, 2011 | 09:56 AM
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Originally Posted by Mel07
What do you mean by lower end or upper end. Sorry, I dont know much about the engine


After you check the oil level have an expierenced mechanic listen to your engine . The older he is the better.

LMO Bill
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Old Oct 18, 2011 | 11:22 AM
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Originally Posted by ZZ71S
Is there oil in it?
I'll go with a quart low.
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Old Oct 18, 2011 | 11:25 AM
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Automatic? Check the torque convertor bolts
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Old Oct 18, 2011 | 11:48 AM
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Do yourself a favor and have someone qualified look at your motor
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Old Oct 18, 2011 | 12:10 PM
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Originally Posted by 69 Chevy
Here's a fact: no 454's were produced before 1970.
Sorry.. yes 427
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Old Oct 18, 2011 | 07:50 PM
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Originally Posted by Easy Mike
I'll go with a quart low.
It would need to be more than 1 quart low to cause a knock .

Bill
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Old Oct 19, 2011 | 11:59 AM
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Thanks for all the input. Its not the oil, that is where it needs to be. I am having it towed on friday to a professional. Fingers crossed it doesn't cost a fortune!
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Old Oct 19, 2011 | 06:57 PM
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Put a timing light on it. Move it from one plug wire to the next until the flash matches the knock and that will locate the cylinder. The the timing of the knock will tell you it it's in the valve train or the bottom end.
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