Long story slightly shorter. 2006 base vette. Bought it with 119k miles in fall of 2017 Had vararam, headers, full exhaust.

Money shift at the strip, clutched in right away but started tapping on return road but then went away. Every once in awhile I would hear faint tapping almost like exhaust leak. Still made good power and no issues other than annoying.

Fall of 2019 now 150k miles, add cam, udp, dual valve springs, new gm oil pump, Due to mileage and slight cam wear shop insisted I do new lifters as well so new set of ls7 lifters installed. Pick it up and the barely noticable tapping is now very noticable. Shop has no idea what it is.

Take it to very reputable LS tuner/shop and he suspects pushrod length is off. Measure several times and it is ok. Play with different oil weights and no real change. Made good power on dyno 450/425 and did alright at track 11.79 at 122 mph with crappy 1.86 60’

It starts up quiet and then about 5 min into warm up it starts tapping, then 5-10 min later it goes away or becomes significantly quieter.

I figured maybe I slightly bent a valve or something. Took it to a different shop (Feb 2021 and 160k miles) and had PRC225’s put on, truntion kit installed, new pushrods, nother set of LS lifters and new trays... pick it up and the ****** thing still taps. The tone changed cause the heads but the only thing left on the top end is the rockers. It made 440/400 on a mustang dyno (tuner aborted baseline when he heard tapping (assumed it was a collapsed lifter). This too is reputable tuner/shop...they did compression test before install and all cylinders were 212-225 and they didnt notice anything.

Any ideas? Sounds top end, rev dependent. This has been going on for 30-40k miles, probably close to 100 passes at the strip, numerous road trips, side trips to mexico, roll racing at the track, etc. i do not baby this thing and it hadnt got worse, but I was certain new heads would solve it.

Apparently it isnt hurting anything but hate my car sounding like it is on its last leg...

this last adventure was $5500 and sure it is a little faster (stock intake holding me back) but this tick is giving me a tick of my own.

No tap on cold start
taps during warm up, quickly gets worse, stays there for about 5 min then starts to quiet down...EVERY TIME! Oil pressure is a little lower than I would like but shop said it is fine. Around 26-30 at warm idle and low 40’s at light cruise. Jumps right up when I rev it

any theorys? Thanks!

 

Piston slap?

 

Piston slap is usually loud on start up and gets quieter. This is always quiet on start and then gets worse as it warms up and then gets slightly better.

not saying it isnt piston slap. 2 different LS mexhanic/tuners said it sounded like wrong pushrod length and a bad lifter. Both were wrong 🤷‍♂️ Maybe slightly bent rod causing piston slap (instead of usual culprits)?

 

When I started reading my first thought was bent valve. We've had a few cars in the shop with a tick that turned out to be the culprit. But, new heads, new lifters, pushrods checked multiple times too. I would bet one of your bearings has a slight issue. When the oil is warming up, maybe you just don't make enough pressure to cover it up. Once it's warmed up, it should flow a little bit better.

 

That’s something I didnt consider. Figured once bearing starts to go, they go! But my only experience with bearing failure is when I spun a rod bearing in my wrx so 🤷‍♂️

Thought about running a can of seafoam thru the motor to see if there was any crud partially blocking an oil passage or something?

any other ideas on keeping her together?

At a point where I am not sure if I wanna put much more into it