Hi All,

My '96 LT1 (54,000 miles) has begun to exhibit an occasional "tic." Sounds like a lifter to me. I've only heard it a few times and it never gives me enough time to jump out and lift the hood. Happens mostly when the engine is warmed up.

I had 1.6 Scorpion Roller Rockers installed about 1,000 miles ago with no issues. I also added LT4 valve springs and retainers, as was suggested here. Could something specific from that install be causing an occasional tic?

Unless the Guru Collective has some alternative possibilities, I may just go ahead and change out the lifters. If I go that route, any suggestions on which lifters to use?

Many thanks in advance of your insights!

Injectors can make a ticking sound, too. You might be able to isolate it by disconnecting one injector at a time while it is running.

I doubt it's the lifters... memory tells me an additional adjustment may be needed on the rockers...

After some spirited driving and lifting the hood, an ear to each valve cover reveals nothing out of the ordinary. Would a noisy injector or out-of-adjustment rocker produce a rare and intermittent noise?

Do you have a mechanic's stethoscope? If not, you can buy one cheap at HF or the parts store.

Are you sure it's from under the hood? Sometimes noises can be hard to trace.

Possible causes already listed were injectors and rockers. If you do indeed find it is lifters, the LS7 lifters are a direct replacement and cost effective.

Quote:

Thanks for the tip on the LS7 lifters. I do have a mechanic's stethoscope and, there is no doubt the noise is coming from under the hood. It follows engine RPM and has occurred while moving (others heard it) as well as while standing still. It's rare (it's only happened twice that I'm aware of) and of short duration when it occurs.

I've only heard it once, in neutral, waiting for my garage door to open. I revved the engine a little to see if it followed RPM. It did. The second time, it was heard by a member of our local Corvette club as I drove past him into a parking lot, revving the engine to make a little noise through my chambered muffler eliminators. I wasn't looking at the tach but I doubt I revved it past 3500 RPM, and just for a second.