Thread: tap, tap, taparoo!

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I have a tapping noise in my 427, the noise seems too be feeding back up through the carb. I tried the ATF trick for sticky lifters and the detergent additives. Its my daily driver, so I was wondering if anyone had any good diagnostic procedures that don't envolve tearing down the motor.....

Post a good sounding video of the noise..........There are about 3 major areas of tap or knock,however you may word it.
Tappin in the heads,usually you can get a clue by removing the valve covers.
Tappin deep in the block it could be a rod ,they like to click or tap ,depending on terminology.
Then there is the knock or thump sound of a crank bearing.
Most engine guys can tell you almost exactly what it is by sound ,by description a tap/tick/knock is really hard to put your finger on over the internet ,but with a video with good sound ,its almost like being right there......

Originally Posted by zero_presence

I have a tapping noise in my 427, the noise seems too be feeding back up through the carb. I tried the ATF trick for sticky lifters and the detergent additives. Its my daily driver, so I was wondering if anyone had any good diagnostic procedures that don't envolve tearing down the motor.....

Welcome,Have you tried the old screw-driver to the ear trick yet??
In other words take a long screw driver and check,valve covers,oil pan etc.
To see where the noise is the loudest.

Actually I used a stethescope to listen didn't really tell me much tho because the motor is so loud. Now I'm running into another issue. Engine ID. I had a reliable source tell me that I should be able to find the number on the flange that sticks out past the cylinder head on the passenger side front of the engine block. The flange was there but it is blank... I also found a source on the internet that said to look just above the timing cover for the #.. I found one, it is "10427xxy" but I have not been able to find a resource that can decode it. I've serched online and called the local gm dealer and fuond nothing......

Originally Posted by zero_presence

Actually I used a stethescope to listen didn't really tell me much tho because the motor is so loud. Now I'm running into another issue. Engine ID. I had a reliable source tell me that I should be able to find the number on the flange that sticks out past the cylinder head on the passenger side front of the engine block. The flange was there but it is blank... I also found a source on the internet that said to look just above the timing cover for the #.. I found one, it is "10427xxy" but I have not been able to find a resource that can decode it. I've serched online and called the local gm dealer and fuond nothing......

If the block has been decked to any degree you won't see the numbers on the flange.

so the "10427xxy" doesn't mean anything? I would think that the 427 would be an indication of engine size at least...Im more worried about what the "xxy" part means... If anyone knows who would know or where I could find out id appreciate it....