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Engine knock

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Old 09-23-2019, 11:31 PM
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Engine knock

Hey so my camaros got a 350 swapped into it and today it started making an aweful sound and im looking for help narrowing down on what it is. When you start it and drive around under about 2500 rpms you can hardly hear anything, maybe a little tick but nothing really noticable. Above about 2500rpm it starts making an aweful knocking sound, sounds like someones beating my oil pan with an air hammer or like a 3/4" air gun that gets worse and worse with rpm and it happens regardless of load. Any ideas would be great thanks.
Old 09-24-2019, 12:36 AM
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Re: Engine knock

First step, I'd pull all the spark plugs and see if they tell a story. Post pictures here if you want help reading the plugs. Make sure you know which plug belongs to which cylinder in case you need to follow up with something.

Meanwhile, might be smart to stop running the engine for now.
Old 09-24-2019, 12:48 AM
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Re: Engine knock

Another thing to check for is a cracked flexplate or loose flexplate bolts (assuming it's an auto transmission).
Old 09-24-2019, 12:55 AM
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Re: Engine knock

Originally Posted by NoEmissions84TA
Another thing to check for is a cracked flexplate or loose flexplate bolts (assuming it's an auto transmission).
Sorry it's a manual, would the same apply for the flywheel?
Old 09-24-2019, 01:28 AM
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Re: Engine knock

It could, just less likely.
Old 09-24-2019, 07:34 AM
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Re: Engine knock

Originally Posted by Julienf
Hey so my camaros got a 350 swapped into it and today it started making an aweful sound and im looking for help narrowing down on what it is. When you start it and drive around under about 2500 rpms you can hardly hear anything, maybe a little tick but nothing really noticable. Above about 2500rpm it starts making an aweful knocking sound, sounds like someones beating my oil pan with an air hammer or like a 3/4" air gun that gets worse and worse with rpm and it happens regardless of load. Any ideas would be great thanks.
It's impossible to diagnose a noise here; there are countless causes of knocks, and you'll have to get under the hood/under the car and track down the source, location-by-location.

Be extremely cautious under the hood with a running engine; the drive belts/pulleys will grab any loose clothing---or fingers.
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