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Updated:.... Found what the tapping noise in my supercharged LS3
Found what was making the tapping noise. It was a peice of ceramic off the plug. I guessing detonation on cylinder 7 destroyed the plug. Car runs fine with new plugs and the tapping is gone. What the next step to check? Did I ruin my block?
Took the Vette out for a drive today. Got about 1/2 mile from the garage and this happened. When shifting in to second and accelerating at 75% throttle the engine sputtered, check engine light came on for just a few seconds. I let off the throttle and heard a tapping. See video. After this video was taken the tapping when away. I let the car sit for a few minuets while checking the codes. No codes, no check engine light. The car has good oil pressure, seems to idle ok while sitting. Have not attempted to drive it. Any ideas or info would be appreciated. The ls3 has a Mild blower grind cam, HD Double Valve Springs, Retainers & Hardened 1 piece push Rods, Procharger with meth injection. The corvette has 11,500 miles and around 7000 miles on engine after supercharger install.
2020 Corvette of the Year Finalist (track prepared)
C6 of Year Winner (track prepared) 2019
The few times I've had plugs let go from detonation it's only ever been the tip of the plug that was damaged. Based on the picture of your plug I'd bet money that you either broke a ring land or a sizeable chunk of the piston is missing.
I wouldn't recommend driving it again until you pull the heads or at a bare minimum look inside with borescope.
Speed Shop Looked inside with a borescope and I saw what looked like scratches on top of the piston. Piston was still solid and did not see any evident cracks. Can you tell if the ring land is broke using the rborescope?
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Originally Posted by subfloor@centurytrans
The few times I've had plugs let go from detonation it's only ever been the tip of the plug that was damaged. Based on the picture of your plug I'd bet money that you either broke a ring land or a sizeable chunk of the piston is missing.
I wouldn't recommend driving it again until you pull the heads or at a bare minimum look inside with borescope.
2020 Corvette of the Year Finalist (track prepared)
C6 of Year Winner (track prepared) 2019
Originally Posted by GS057
Speed Shop Looked inside with a borescope and I saw what looked like scratches on top of the piston. Piston was still solid and did not see any evident cracks. Can you tell if the ring land is broke using the rborescope?
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Yeah, you should be able to see it with the borescope. With the one I have it's a little bit difficult to move around in the cylinder properly to see all of the piston, so I've had damage before that I wasn't able to see until I actually pulled the head.
If you're certain they were able see the entire piston then you might be okay. The other thing you may have to contend with is some of the debris got down in between the cylinder wall and piston and damaged one or more of the rings (once again, speaking from experience).
When it happened to me the damage was only moderate in that the numbers from doing both a compression and leakdown test were outside of the normal range but there was only a very marginal drop in performance so I didn't bother pulling the engine.
That's a big chunk of ceramic missing. I have detonated some plugs in my day and the leak down/compression always came back ok on my Ls1. So here's hoping.
10-21-2014, 10:36 PM
Updated:.... Found what the tapping noise in my supercharged LS3
