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#1 |
Join Date: Mar 2024
Location: Northeast
Posts: 41
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While warming my car up on an easy drive to troubleshoot a hot start issue it abruptly started making a loud ticking noise. This happened off throttle going down a hill at 30mph in 3rd gear. The car was fully warmed up at the time. Oil pressure seemed normal before and after. The engine seemed to run rough for a few seconds and the noise got better, but was still loud. I drove it 1/4th mile, took this video and shut it down. I have not attempted to start it. It sounds like a lifter, but some people on fb suggested it might be a chain tensioner or a coil pack.
https://youtube.com/shorts/bMqIPn26r...JLZIm1N9ZcjiIc |
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#2 |
![]() Join Date: Jul 2015
Location: Ypsilanti, MI
Posts: 116
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Useful when troubleshooting to be able to prove things out quickly so the true issue can be found.
I can?t comment on lifters or chain tensioners so I?ll leave that to more qualified folks here. That said, I do have experience with a coil pack failure. Coil packs can be checked pretty easily with no real tear-down by getting resistance readings through the spark plug wire ends. They should all read similar ohm values. Plug pairs per coil are: 1/6, 2/3, 4/7, 5/8. When it happened to me the car got really loud on the exhaust note and idle was super rough. Turned out I had open circuit on one of my coil packs. Sent from my iPhone using ZR-1 Net Registry
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1991 ZR-1 #1438 Black/Black & Red |
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#3 |
Join Date: Mar 2024
Location: Northeast
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Update on this. I pulled the left side spark plugs and put a borescope down the cylinders. The plug from the rear cylinder seemed to be a little wet and dark. Picture is attached. Hopefully something didn?t get into that cylinder and bounce around. The bore scope showed a wet piston with carbon buildup. There are reflective spots that can be seen and I can?t tell if that?s glare or if it is actually shiny metal. I put everything back together and fired it up and the noise wasnt as loud. I then pulled the plug again and had a look down. No real changes. I started it back up again and revved it to about 3k and the noise seemed to almost go away, and stay away. The oil was changed in February but it looked like there was some sludge on the bottom of the dipstick. I was told the car sat for several years before that. Is it possible something just got into one of the lifters and temporarily affected the oil flow? The next step is to change the oil again.
https://youtube.com/shorts/qtXyKD6Wm...nlxeizijrzQ7Db https://youtube.com/shorts/JgwCl0Oce...79X1G6zw8v4KE7 Last edited by Tim555; 05-30-2024 at 08:03 AM. |
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#4 |
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Location: Japan
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Craig "ZR-1 NO KA 'OI" "ZR-1 ICHIBAN" 1995 #228 Black/Black with Dunn Heads ZR-1 owner since September 2003 ZR-1 Net Registry Founding Member #0074 NCM Lifetime Member #2048 ![]() |
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#5 | |
Join Date: Mar 2024
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#6 | |
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https://www.corvetteforum.com/forums...oil-packs.html
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Craig "ZR-1 NO KA 'OI" "ZR-1 ICHIBAN" 1995 #228 Black/Black with Dunn Heads ZR-1 owner since September 2003 ZR-1 Net Registry Founding Member #0074 NCM Lifetime Member #2048 ![]() |
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Join Date: Mar 2024
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#8 |
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Craig "ZR-1 NO KA 'OI" "ZR-1 ICHIBAN" 1995 #228 Black/Black with Dunn Heads ZR-1 owner since September 2003 ZR-1 Net Registry Founding Member #0074 NCM Lifetime Member #2048 ![]() |
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#9 |
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Lots of good advice here, but I would be remiss if I didn't once again post my idea for the strange ticking sound. --Bob
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2016 Long Beach Red Z06 #10281 "POPS Z" 1995 Polo Green #409 "WARP TEN"--Haibeck 350/510 package, 4.10s, Hurst, Stock Exhaust with QTP Cutouts --Sold but still running strong 1993 Quasar Blue #161 "HIL KING" --Sold but still running strong, now with more than 120,000 miles 1967 Marlboro Maroon/Saddle Corvette Coupe 300 hp/4-spd --Sold a long time ago ZR-1 Net Registry Founding Member #95 NCM Lifetime Member Favorite Quote--Attributed to Mickey Thompson: "Too Much Horsepower is Almost Enough" |
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#10 |
![]() Join Date: Jul 2004
Location: Kalamazoo MI
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Maybe that's my ticking sound as well, shows up out of nowhere and I can't figure out where its coming from sounds like its under the plenum on mine as well.
The problem is I just replaced them damn coil packs last summer.
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JOHNNY P Currently own 90 ZR-1 #845 DRM 500 engine package 90 #226 Parts car Hit me up if you need anything. |
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