This pertains to the C6 Vert I just bought but you guys have more general knowledge of how stuff works i have found ove the years so i come to you as a C4 owner for help

My brand new car vibrates at 70mph. I am still breaking it in so i am not supposed to go over 55 but try that on an atlanta highway. Anyway today was the first day ont he highway and i took it out just now as well here is the deal

it is smooth as a babys bottom all the way to 70. Right at 70 i get a decent vibration through the steering wheel like the front wheels are out of balance. I have not pushed it up into the 80's to see if it goes away but......

If i turn the wheel left or right at 70 it goes away. I was thinking is i turned it one way and it went away and the other way same or worse then its a wheel bearing but it goes away as long as the wheel is not dead center.

Its not the engine or anything like that i had it stopped in my draiveway and with the clutch both in and out there is no vibration at all as i move through the powerband

Is this just a simple wheel out of balance or is there more to it. I called the dealership today and they could not tell me much, one told me i had to give it a few hundred miles for the car to "synchronize" LOL what absurdity

Anyway you guys know your stuff, what do you think. I dont even want to take it to the dealer. Balance / Alignment / more???????

 

Absolutely unacceptable on a 60,000 dollar new car, especially a Vette. You could always demand the dealership perform a Hunter RoadForce balance on the front wheels. My money's on a slight inperfection in one of the front tires.

Nice to see you in C4 Gen again.

 

Thata thing dont even happen in my 85 vette even at 120 mph its steady and hug the road. I would have contacted the dealer where u bought it, if not than i would recommend my mech he just got brand new Snap On balance m/c and infact he did it all my wheels for free.

Robert its time to change avatar pic and Zip code in ur profile.

aru late night person, if so than i can hang with or just drop over ur home to just say hi, shoot me ur address in a pm. I dont drink but i can give u company. I work eve shift in douglasville, GA and live by myself u r most welcome my home. sami.

 

Update

Ok i guess i was wrong. It does still vibrate about the same when turning left to right at those speeds. I also took it up faster on my way into grad school this morning (i won't say how fast but fast and it doesnt go away but seems to minimize as it gets fast (it was really to hard to tell to be honest i just know it starts at 70 and turning doesnt fix it after looking at it closely

I am now leaning towards a simple out of balance wheel. I cant tell about the vibration but on the smoothest parts of the highway but it is very discernamble at 70 mph at highway speeds, you can see the wheel shake it you let go of it. Car tracks in a deal straight line, seems to be perfectly alinged.

Your thoughts? Simple wheel balance issue?? I hope so. I was worried it might be wheel bearings but the car is silky smooth exect for the 70+ area and there is no noise.

Let me know what you think

 

Get the tires balanced first. That would be my first guess.

 

Sounds like you kind of knew what the problem was already, or the possible problems. Who told you you can't take a new car over 55?

 

Right, they say vary your speed(engine and car).

I was alwyas told to break it in like you're going to drive it, so my first new car(truck) I did a burnout out of the dealership and never looked back. Beat the crap out of it and 193,000 miles later I finally sold it. It has a third owner now and is still going.

 

I am up to 100 miles now and i am leaning away fromt he rules of break in just a tiny bit. I am starting to rev it higher. The way i understand it is the breakin is really for the rear end, and tranny more than the engine. I am going to exercise due dilligence but keeping it under 55, please

See saw triple digits (I stopped at the racetrack on the way to school to be safe) and i think that s fine

 

General rule of thumb for break-in you want to maximize cylinder pressures but keep rpm's below 75% of redline for the first 1000 miles, this will ensure optimum seating of the piston rings which will ensure maximum compression by the cylinders over the life of the engine. So this would mean use hard acceleration often but keep the rpm's below 75% of your redline. I don't know the redline on the LS2 but if it was, say, 6000 that would mean stay below 4500 for the first 1000 miles. Another benefit is it minimizes oil consumption over the life of the engine (optimum ring seating = low oil usage).

 

Thats a funny number because thats exactly what i have been keeping it to. I took it to 6,000 only once to just feel it but 4500 is more that adequate for most driving anyway

 

when i saw the thread title, i thought to myself, "self, you can probably help this guy if he is in atlanta.."
i had the exact symptoms you describe on my '94 after switching to zr1 sized rims and tires.. i had discount tire balance and rebalance them many many times.. never could solve it..
but then, i was having a conversation with a bunch of old timers at a car meet in atlanta (i was passing through) and they instantly agreed tire balance problems. they all swore off automatic balancers used these days and insisted i must go see a guy around the corner who still balances tires manually. that garage was in atlanta. the old man will put the car up just high enough to get all four wheels off the ground and then use a high speed roller to get the wheels spinning while mounted on the car. with an assistant in the drivers seat, a hand on the steering wheel and the guy by the tire with a hand on the fender, they'll move the weights around until there is no vibration. i was truly amazed at how smooth the car is at any speed, even up over 150mph now.
So anyhow, the place is Gran Turismo East, call Harris Conner 770-455-0347. Tell him a friend of Dick Anderson's sent you.. Dick used to own Carrera shocks and has raced many things over his long career..

 

Wow.. came here again to see if there was anything that might help me figure out what the heck has gone wrong with my '94 with 125k miles. Developed a bad sound (no vibration or feel to it, though) at 45mph and above, scary bad at 60+. Took it to Goodyear - not my regular one that's given me great service and troubleshooting for about 10 years but a closer one - they said ball joints, replaced them ($600) and it seemed fine. ALSO had them do a tire rotation (Bridgestone Potenzas, about 15k miles on them now) and 4 wheel alignment.

But a new sound surfaced, and again at 45mph you hear it not feel it, at 60+ it's just plain scary. whump whump kinda thing that is definitely wheel noise.. as before, I thought bearings or, the new brakes were installed badly.. they put it on the lift and drove it twice since now and 'see' no problem but now I get it, I bet they screwed up the BALANCING, right?

So I'll have them rebalance and take this thread with me when I do so!

Thanks guys, I'll let you know what happens.

 

I think it's wheel balance! Bad factory balance. Also look on both sides of your wheels and see if one one them has a lot more weight than the others. If so that's your bad boy. It takes a while for the tires to set to the rims. The dealer should rebalance at your first service but I would get it on your service record ASAP in case they give you trouble.

 

Heard good things about GT as mentioned above. My personal choice is Butler Tire. Many locations around the ATL.

--Tor

 

 

It sounds like a wheel balance issue. When you take it in, insist on a road force balance.

 

In this order, since you just bought it, do what J-J sez. Then, try Mikey's suggestion, but you shouldn't have to: the place you bought it from "owes you".

 

Tried to attach the pics of my wheel balance scenario, can't see how to do it here BUT, 3 of 4 wheels have weights on outer and inner rim; driver side rear wheel has only 1 (inner rim) weight.

The front wheels both have the largest weights on them of the 4 wheels (inner; outer weights of the smaller variety). And it's from the front I'm hearing, though not feeling, this awful thwumping rotating sound that increases with speed as I said earlier, similar to Roberts problem at start of this thread.

So I'm having Goodyear redo this balance job; the tires need to be rotated, I can't just keep the same (heavily balanced) tires on the rear wheels permanently. Thanks to BadDuck for the tip.

 

The person who told you that was lying to you.

I agree 100%.

Larry
code5coupe

 

To make a long story short thedealer said they neded my car for a day or two and would send it to their tire place. What a joke. I took it to discount tire where i know the people well and the road force balanced the tires on the Hunter 9700 machine. Sure enough one of the front wheels was way messed up from the factory. The wheel was fine but it told him that the tire could not be balanced. They took 45 minutes to rotate the tire around on the wheel and go through several cycles on the machine and it balance out perfect with minimal wheel weights

They took anothe half hour and rebalance my other front tire on the hunter road force machine and it balanced our perfect

Car now is vibration free and perfect. Why in the heck can't GM get it right out of the plant. There was a ton of weight on the offending wheel and obviously they did not care to balance it right

I am out 50 bucks because i did not care to deal with the dealership and thier BS. At first they told me the car needed time to "synchonize". Thik i can get my 50 bucks back LOL

BTW in case anyone wanted to know (most probably do but i did not) the chrome wheels are made by speedline in Italy. It's stamped inthe back.

I love Corvettes but i'll never own any other GM products. Thank God they make the corvette though. Best car under 100 large by far IMO

At least all it was was a balancing issue, i am still steamed that I had to spend 50 bucks already on a 55k dollar car with 173 miles on it