regorih383

iTrader: (21)

I need a little help finding a loud ticking sound that happened after a buddy accidently dropped his C6 LS2 A6 from 3rd gear to 1st gear causing the motor to over rev fast to 7k rpms. I pulled the heads expecting to find a bend valve or some contact marks on the top of the pistons but they all looked normal and no evidence of piston to valve contact.

I also inspected all the lifter and they all looked normal too. Right before I tore the engine down the loud ticking sound was present and it would get louder as RPMs would increase.

Does anyone have any suggestions on where else to look? I’m hoping that the loud ticking sound isn’t coming from the short block.

Thanks,
Roger





*EDIT 8-3-15 I got the engine back together and the ticking sound is gone. I did h/c package with new lifter so I can only assume a lifter took a dump. Thanks for the comments*

joeformula

iTrader: (11)

Sounds like a bent pushrod. I did this many times when I first got my car

78novacaine

iTrader: (2)

I gotta ask, how did he miss a gear with an automatic transmission?

regorih383

iTrader: (21)

The paddles on the steeringwheel are opposite from factory settings and he was trying to go from 3rd gear to 5th gear.

ramairetransam

iTrader: (18)

did you roll the pushrods on a flat surface to see if they are bent? and is it possible it has an exhaust leak ? but more than likely this is a bent pushrod , it happened to me once .

regorih383

iTrader: (21)

Thanks, It never occured to check the pushrods. I'll take a look and pray.

Thanks again

NemeSS

iTrader: (127)

Palo doblado

7beast

iTrader: (30)

Lmao

audacious nick

Yeah, but it won't let you do that. You can push the downshift padde as much as you want, it'll just pop up and "x" and won't downshift. Did he **** with his tune and override that safety feature that's specifically designed to prevent this?

regorih383

iTrader: (21)

I'm not sure about the tune thing. The car came that way.

Also all the pushrods look ok.

audacious nick

He needs to get that checked out, as well. The car should not allow him to shift into a gear that will overrev the engine. Coming from a C6, I have occasionally hit the downshift paddle by accident and get the annoying chime and "x" on the HUD.

Since you're in there, you might as well replace the lifters, trays, and pushrods.

Did you remove the valves and make sure there is no damage on them?

78novacaine

iTrader: (2)

My ls2 chewed up some lifters a few years back, when it started ticking again I thought it was the same issue, it wound up spinning a bearing though, hopefully that is not the case with your buddy's...

DarknessHunter

iTrader: (10)

Sounds like bearings are shot, happen to me when my friend over revved my formula

00pooterSS

iTrader: (40)

Rotate the crank around with the heads off and while the pistons are on the down stroke push on them and see if any drop. There should be no movement at all. If you can get one to move down even a hair then you've found your worn bearing that is causing the noise.. However, I would highly doubt it spun a bearing if it only over revved for a very quick moment, especially if it really only went to 7k. If you had the rev limiter at 7k and were hitting it all the time I would suspect a bearing, but usually a quick over rev damages the valve train.

Does it have an after market cam & or valve springs? If so the springs probably kept the valves in check, if the springs are stock I would really look at all the valve train and suspect only that.

Good luck


Edit: for what it's worth I revved my 00 SS with a stock internal LS1 (except valve springs) to 6800 every day multiple times a day until it hit about 175k then took it down to 6700 RPM and it went over 200k and is still going. I rev my truck to 6500 pretty much daily with a bone stock 5.3 and it's fine at 145k miles. An LS2 should take a 7k rev no problem, unless there is something really wrong with LS2 rod bolts over other LS motors or the oil was in **** shape in that motor. I spun a bearing at 8k one day and it was a car I took to 8k daily for 2 years, but on this day it only had 2 quarts of oil in it.. oops. How much oil is in the Vette? How old is it? If the answer to either isn't a good one then yeah it may have hurt the bottom end.

regorih383

iTrader: (21)

After the over rev incident the engine had good oil pressure @ 40-45 psi cold start at idle and 38-40psi hot. That ticking sound was definitely coming from the top end of the engine. The engine is torn down and short block looks normal. I’m going to move forward with AI heads, Texas Speed camshaft, new lifters, pushrods, trays, and oil pump.

ALenzSs

I had good oil pressure when one of my crank bearings decided to commit suicide. I used a mechanics stethoscope to give me a good idea where the noise was coming from before I started digging into the motor. It was obvious lower end issue as it almost blew out my ear drums. Great cheap little tool. Little late to use now. Have you checked the oil you drained out for any metal flakes? You can also cut the oil filter open to look for debri as well.

zero2sixT

iTrader: (4)

That's what I would do. Not find out what the cause of the noise was and then dump $3k into it...

regorih383

iTrader: (21)

Oil looks normal, and no metal meterial in the filter

grinder11

iTrader: (1)

I Over-Revved my LS7 recently. It has gone over 1 thousand miles since this happened, and has an intermittent noise I believe is somewhere in the valvetrain. Why? Because several pushrods were bent and were replaced. After installing new pushrods, the noise persisted. It seemed worst around 2000RPM, not at idle. Recently, after accumulating those 1,000+ miles, I took my 14 year old Grandson for a ride. After almost an entire Summer of grandma (pa?) driving, I decided to light 'm up!! The motor only reached 5,000 RPM, but the spike in oil pressure seemed to have an effect. The noise vanished. I know it needs to come apart-BUT-I need to he the one to do it-NOT let it go until it takes itself apart!! My point is: Only 1 thing in the valvetrain would be affected by oil pressure: The hydraulic lifters!!!! I'm thinking an internal part of the lifter, a check valve-Something internal-Inside the lifter itself, was damaged. Just my 02.

grinder11

iTrader: (1)

I agree that it sounds like only an idiot could do this, but it happened to me, and I don't consider myself to be an idiot! However, I had the car in for a dyno tune at what I considered (at that point in time) to be a well respected shop in Wixom, Michigan. Long story as short as possible: they blew it-Badly! The rev limiter was set at 7,000 RPM(since verified at another shop), but it was not "applied"! Anyway, I hadn't had the car on the road in years, and when I last did, I didn't regularly drive at 140MPH down the interstate!!!! Especially with an 82 year young woman in the passenger seat beside me! She's my Father-in-Laws girl friend, and crazy about hi performance cars. She had once bought a Then-Brand-New 1965 Mustang, and loved to go fast. I was having problems with the 4l60E trans BEFORE this shop tried to do the tune, so I told them about it. After the tune, they said they had found the problem, and fixed it. Well, at around 140 MPH, foot to the floor, I shifted into overdrive. It was never engaged, and the motor just screamed-Probably hit at least 7,800+RPM before I could get out of it. But this old, young at heart lady had the thrill of her life!!!! I then drove the car 150 miles home. I have since put another 800-1,000 additional, easy miles on it. I got tired of seeing it sit in the garage with this as yet undiagnosed problem, afraid to really get on it, so I am in the process of tearing it down as I post this. I promise that as soon as I know what went wrong, I will post-up. But-YES-I have seen for myself just how "anyone" could miss a gear with an Automatic Transmission!!!!!