Engine noise- stuck lifter?

[Tim555]

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

[KPW]

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.


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[Tim555]

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

[HAWAIIZR-1]

Another vote for failed coil pack.


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[Tim555]

Originally Posted by HAWAIIZR-1

Another vote for failed coil pack.


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Is that driver side back cylinder #7? Do I just test for resistance between the ends of the 7 and 4 spark plug wires?

[HAWAIIZR-1]

Originally Posted by Tim555

Is that driver side back cylinder #7? Do I just test for resistance between the ends of the 7 and 4 spark plug wires?

Here is what I could find. It was the same problem I had years ago and thought the worst and it was just a coil pack. I hope same for you.

https://www.corvetteforum.com/forums...oil-packs.html

[Tim555]

Originally Posted by HAWAIIZR-1

Here is what I could find. It was the same problem I had years ago and thought the worst and it was just a coil pack. I hope same for you.

https://www.corvetteforum.com/forums...oil-packs.html

Thanks for the link. I hope so too!

[HAWAIIZR-1]

Originally Posted by Tim555

Thanks for the link. I hope so too!

YW. 🙏🏼 🤙🏼

[WARP TEN]

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

[phrogs]

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.