jerich0

almost 2500miles, and in the last 2 days, i've started to notice an odd rattle, buzzing sound that comes from the front of the car. it doesn't happen when idle, and while i've tried, i've not been able to catch it on video.

I thought it could be throttle related, but it doesn't seem that way, throttle response isn't affected, and doesn't seem directly co-related. i also thought it could be something to do with the timing belts (honestly didn't read the thread about this carefully either), but i'm assuming if it's the belt, it'll be pretty consistent, and happens at regular intervals.

The rattle sounds like a license plate vibrating, and it usually starts soft, then loud, then goes away. with the roof off, you can hear it, and it's pretty loud, with the roof on, it becomes more like a buzz. Oddly, with roof on, there sounds like a small fluid rush before the buzz sets in. (note i don't have a front plate on, so it's not a plate issue)

i know this means i have to bring it into the dealer, but it will likely mean they will need quite time time to diagnose. I'm hoping to do some initial troubleshooting before they look at it, so it will not be an exploratory session. I'm not super familiar with what's under the hood, but am a good listener, i used a torchlight to look under the hood, and did not see any fluid leaks or anything out of the ordinary (i was looking for stuff like loose clips etc.).

Any suggestions folks? i'm hoping this is not a sign of a possible larger failure. Oh, and for folks that care, my car is in the low 6000s VIN.

thanks in advance!

slief

Check the belt tensioner pulley for oil leaking out. It sounds like your belt tensioner could have lost its fluid and gone bad.

jerich0

any chance you can point out where i should look (i have attached a photo, let me know which corner to look). Note that i did not see any fluid leak on the garage floor, i assume if there is oil, it would be on the floor?

kp

http://forums.corvetteforum.com/c7-g...de-anyone.html

This post may help you out, I posted a pic of the tensioner and where its located. Hard to tell if its leaking from the top, easy to spot from underneath.

jerich0

Thanks, this helps alot. Question on being able to drive the car safely... if it is indeed the tensioner, when the oil runs out does the engine overheat? Car is my daily driver and I am trying to figure out when I can get to the dealership.

doneski

I had the same issue, my belt tensioner was leaking. I took it into the dealer and they "fixed it." But now I hear a deep throttle noise when I accelerate. Like not in a good way.

wgood

I also had some buzzing but no rattle What I did was look at hoses and etc to see if some plastic parts are touching other parts So I took some self adhesive pads and placed them under the L shaped hoses and under the " Corvette " covers since more air passes over the engine with the hood vent !!! See attached picture !!!I also made sure to run the HVAC at the highest setting and open and close vents to see if sometime got caught in the system and in my case I ran over some small tumble weeds !!!! Wayne

kp

The oil is just in the tensioner itself and its there just to dampen vibrations. Even if it goes dry the spring will still hold tension, just will have a loud chirp when its in V4 at times. Mine went around 1000 miles before it stopped leaking and the noise was pretty obvious, it was leaking the day I brought it home new.

Takes about 15-20 minutes to change it.

You have to remove the intake elbow/silencer to change the tensioner, at least it makes it much easier.

If the noise is coming from the front of the car most likely they didnt attach the lower part that 'hooks' into the plenum at the air filter base. Want to make sure thats not the case since you could be sucking unfiltered air into the engine.

Right at 2:45 in this video you can see it off the car and in the small inset, the tabs have to be in the slots on the bottom, if you miss will be wide open at the bottom. If this all started after the tensioner then have them look at it if you cant.

Michael A

You might check for loose exhaust heat shields.

If it was coming from the back, I would point to the exhaust valves.

Michael

Vette-Pilot

For what is worth, I had a similar problem on my C6. After a lot of taping and test driving with the service manager, we found that it was the seal on the bottom of the windshield. It is pliable and air turbulence would make it vibrate in an area about three inched long. a small piece of double stick tape solved the problem. That is the only instance that I have read similar to this so it may have been a one of a kind event. Just giving you the benefit of that experience.

kp

That was the C6 cowl trim farting/buzzing, very common C6 issue. They changed the cowl on the C7 redesign and no more buzzing.

bglmn

....just a wild guess: check your driver's side shock absorber, to see if it's loose.

TKay

If it were me, I would try to pinpoint exactly when it does it. Then go to the dealer and take the mech for a ride and duplicate what it is doing. That will give him a head start on what to look for.

Vette-Pilot

Good. Thanks for the info.

doneski

Went to the dealer and took the tech for a ride. He told me that the noise I was hearing was normal. He said that i reach a plateau while going 40-50. And then when I press in the gas to give it some push, that's when I hear the throaty rasp... He said that's the nature of the v8. It only lasts for a second or two. And then it sounds like normal acceleration.... Anyone else hear it?

kp

Hard to tell without driving your car, if it never made the noise before they worked on it then something changed. But sometimes people pay more attention to noises after a car is worked on and notice something that may have been there for a while.

jerich0

Brought my car in today. They claimed tsb number from other post was wrong, but they found another. However they need to disable the car to fix ?!? and it takes some time to re enable. All this for a belt tensioner rattle? So they want to keep it another day. Sigh. What can I do, say no? Also the fix for my other issue (clipped emblem on seat) requires them to likely change the entire seat cover, ok, how long is that going to take. I'm losing faith in Chevy service actually knowing how to take care of people who bought a 70k car they are so lucky the car drive so great. 😞

jerich0

Anyone know what "disabling the car" means? i've been searching the site, but i can't find any reference to this - does this have anything to do with the security system in the car? why would replacing a belt tensioner have anything to do with disabling the car?

Chevy Cust Svc

Hello,

I realize how displeasing it can be when faced with service concerns like these, and would be happy to seek any additional information/clarification on the service process if you'd like. I can communicate this with the designated Customer Experience Manager at your dealer if necessary. Feel free to message us privately if you'd like to proceed, or discuss this situation further.

William R.
Chevrolet Customer Care

jerich0

I'm talking with Chevy customer care offline and they have been super responsive. That said, i have to rant here again. I just got my car back today, after 2 days of being left at the dealer. 3 things to look at, result - nothing done. why? remember they had to disable the car? well, no, they decided they had to order the belt tensioner, so they couldn't do anything. They also are ordering the wheel liner. To make it super worth while, they decided there are no parts they can order to fix the clipped emblem.

Woop-tee-doo... 48 hours gone, nothing done. nada. Absolutely fricking waste of time. Love the car, hate the service.