white noise sound behind your center dash console?

[mgg]

Lance, I find you post regarding the "white" noise very interesting. I to have a shshshshshing sound behind the radio / vent area and have not been able to identify what the noise is and where it is coming from. It is not so bothersome as much as I am curious as to what it is. I seemed to notice mine after I had installed my headers. I hace checked and double checked and the headers are on fine with no leaks and actually inatalled much better thna was the factory exhaust manifolds. When I saw you post I has to laugh as I though I was the only one who experienced this and it sounds like the same issue. I am disapointed that you sound deading material did not work out like you wanted it to. If you are heading up to WAZOO and need to take a break on your drive, I am located in Hamilton, VA. YOu will probably drive right by me heading up from Chester, VA. If you need to take a pit stop you are more than welcome. I appreciate your article. Let me know if you think you might stop by.

[LancePearson]

Originally Posted by mgg

Lance, I find you post regarding the "white" noise very interesting. I to have a shshshshshing sound behind the radio / vent area and have not been able to identify what the noise is and where it is coming from. .

MGG...Thanks for the invite. I hope to be going up I81 and Winchester is only about 20 miles each way from there so I'll keep it in mind. Right now I'm hoping it's good enough to drive the Z which has a new serpentine belt, etc. but that depends on the weather. If it's cold, wet and any snow at all up in the Blue Ridge then I might leave it at home and drive my TBSS with its LS2 2008 engine and 4:10 rear end and all wheel drive instead and take the more direct route. The plan is to go West on route 60 to Amherst, Va. then to the Blue Ridge Parkway and take it north for about 50 miles to Waynesboro then skip over to I 81 and on up to Carlisle the 5th for the 6th deal with the Wazoo group at Miller's in Carlisle. Looking forward to it but if there is any ice, snow or truly miserable weather the new Goodyears which are excellent on dry or wet roads are absolute disasters on snow. Like snowboards at best! In any event, I am hoping it's warm enough I can go up with the targa top in the back even if I have to use the heater with the windows up but we'll see what the weather says first.

With respect to the noise, I bought my Z N of Atlanta in early Dec., flew in Sat. morning, paid for it and got in it, stopped at the store for a couple things then drove it over two days to Virginia at 73 mph and loved it but the top was on with the targa in the back and the white noise sounded like a "whooshing" sound to me too...white noise I call it and it was below the dash top and behind the electronics stack in the center of the car. I was only concerned with function and the tranny worked great but I knew the water flow was different on the LT5 and all gauges and fluids checked perfectly so I drove it and had the mechanic look as well. We all concluded that it's just the ZF 6 speed with its barely beveled if at all depending on what year you have heavy duty gears making a sound as square cut gears do I'm told. So, when I took the radio out to reface it I checked the shift boots to be sure one was not torn, etc.. What I discovered is that there is a fair amount of 1/2" sort of fibrous insulation between the tranny and the interior, far superior to what my 76 came with, and it does a serviceable job on the noise except in that one area. You have seen my first attempt at damping the resonance of the thin plastic supports that hold the stack. Didn't really work much. Next time I open the center trim face and remove it I will just stuff some fiberglass insulation in the cave below the radio but I suspect that won't stop it either. I think it just works its way in and gets trapped between the fire wall and the center glove box and that's where you hear it.

In my case I have a couple of black microfiber towels that I fold about 4" wide and lay one on the cigarette lighter and the other across the front and up that center trim which hides the empty cave and the white noise, shshing and sound goes down by more than half so I think I know the place. it's not worth it to me to open it up again when it looks so nice now but when I do I'll try one last time with fiberglass stuffed minus the paper into the cave and maybe around it. The glass is not combustible so it should under any circumstances be good there.

The truth is that since I drive mine mostly with the Targa top off on good days so it's easier for me to get in and out the wind eliminates the noise to begin with and it's not an issue. I've sort of grown to accept it and am just happy that it isn't some mechanical or valve failure on the water system. When you look at the engine and the firewall relative to the dash the ZF is right below that area leading to the bellhousing and the back of the engine so it just about has to be noise from the tranny's gears or perhaps in some odd way the unusual flywheel arrangement. In any event, it is not so far worth the expense of digging into all that. Putting headers in did you notice any insulation between the bell housing and the interior? My 76 has a foam piece cut to fit to try and minimize that noise and I don't know what's on the back of the bell housing on our cars. If there is perhaps both ours has fallen out or disappeared. Truly, I haven't looked or noticed anything like it in the manual looking I've done so far but they used to do it on the C3's. I have a 76 in the garage right next to the 91, both Bright Red from 1991...someone else painted the 76.

No one else has chimed in since I think it's a non issue for most who hammer their cars with big exhausts anyway but I had a 515 mile drive in a new to me car to fret about it so I did.

Funny thing about my exhaust which is a couple Borla's and that system which I like well enough that was on the car, I hear it when I'm running the car up through the gears but from about 50 or 70 or some mph when I'm zipping along that sound is so far behind me I can't hear it anymore and I'm concentrating. I know at any three digit number up to the 140ish I've had her loafing in fourth gear that there ain't any sound and the white noise meant not one single thing to me. Lots more things to think about, very fast thinking, at 205 feet per second...2/3rds of a cotton picking football field every second.

I still like the signature line of one owner here which is irreverent as can be but is true: "I can break every single speed law in the United States and still be in second gear." True.

Glad you liked the article. There is another one the HOTB folks already have as well. I set out to buy a c5 or c6 and stopped when I saw the LT5...it's just amazing with all due respect to the C5's and C6's.

Lance

[B17 Crew]

Hello, Mr. Pearson.

Your post reminded me of a similar sound I had experienced with a ’94 LT1 6-speed coupe I used to own. I had approximately 55,000 miles on the ’94 when it needed a new clutch.

Had a local Chevy dealer perform the work; picked up the car and it functioned perfectly. I did however notice a “whooshing” sound coming from my center console. When I would open my ashtray door, the sound was more pronounced (louder) with the ashtray door open. This sound had never occurred until after the new clutch had been installed. I determined that the dealer must not have placed part or all of the sound insulation back in place properly when they were buttoning up the car. I had the targa-top off most of time when driving this car, so it didn't bother me too much. I ended up trading the LT1 for my LT4 (my current car) so I never really found out what the exact cause of the sound was.

I was wondering if your Z is on the original clutch or if the clutch has ever been replaced. Although, your sound anomaly sounds as if it’s originating further forward than what I had experienced.

I visit this forum quite often and I wanted to mention that I always enjoy reading about your driving experiences you have with your Z.


B17 Crew

[LancePearson]

B17, probably the original clutch though the ZF six speed tranny underneath the car has a blue metal tag on it saying "rebuilt to GM specifications" so it might be newer than that. Some early Z's had one version of the ZF and some later had another and they were differentiated by labels and from what I read, the later version had slightly different beveling on the gears. Original were what I'm told were "square cut" with no bevel and the later ones had a slight bevel. Square cuts, I'm told, will always be somewhat noisier but can stand a ton of force. I don't personally know what's in mine and am only repeating what I remember from reading other's posts other than what's on my tag on the tranny.

I am glad you enjoy the experiences of all of us as I know we all sure enjoy having them. I bought my Z in early Dec. n. of Atlanta and drove it home. It was in great shape but did not have an owners manual or maintenance records. I did have a Carfax and knew the brakes were serviced 7,000 miles before I got it, the fluids were fine and it drove well, clutch and tranny included though the "whooshing" sound was different for me and made me fret a little. When I got it home I had my shop go through and change ALL the fluids including tranny and rear end so I'd know their provenance and just last week had the serpentine belt and the pulley on the belt tensioner changed so I know their provenance at 45,000 miles. The belt was okay but the pulley needed changing but we put all new in regardless. All working well.

I have about 700 miles of driving it coming up to go to and from an all day Wazoo event at the Millers in Carlisle, Pa April 5,6,7 where I'll go west and hit the Blue Ridge Parkway and do about 50 miles of it then skip over to I 81 and go N. to Carlisle to watch the group tear into and replace a set of injectors on a Z, lunch, then see the Miller car collection, dinner with these terrific owners then home Sunday. The long, looping but scenic way around, weather permitting. If the weather is bad I'll go more directly. Then I may take it to VIR May 4,5 to watch some other Z's run the track in a TrackDaze event with my cameras if they are still going to do it, then May 15 head for Bowling Green and the gathering which is 646 miles each way.

I have a 76 with 100,000 miles on it and the clutch still works fine on it. The Z's is the smoothest clutch I've ever seen.....hydraulic instead of mechanical. Don't know what it's life will be but I suspect it depends on how they are used to some degree. I'm easy on clutches personally.

Lance

[secondchance]

Lance, B17 crew,

A couple of things - when transmission work is performed and transmission is dropped rubber boot under the console is often pulled down with the shifter unintentionally. After the transmission service as the car is being buttoned up most mechanics are too careless to install the rubber boot carefully and left side of the rubber boot is rarely secured over the lip on fiberglass body trans tunnel. Trying to slip the rubber boot over the lip is impossible fromthe top without almost total disassembly of seat, console side panel, etc... B17 crew noticing more noise with the ashtry door open is indicative of this. Solution would be removal of driver seat, console trims, console side panel to gain access to the left side of the rubber boot and slip the edge over the lip on the tunnel.

Another area to check is the map sensor hose. I had a situation where the map sensor hose was loose between the rubber boot and hard plastic line resulting in vacuum air leak. This also make a subtle loss of drivability and I emphasize subtle. In my case resealing of MAP hose cured the noise also.

[LancePearson]

Second Chance....thanks for the insights. My boots, the rubber big one then the leather over are fine and the noise really isn't below my ashtray but forward and behind the radio so since I just ordered the Maps plaque when it comes I'll look around back there and be sure it isn't the hose. Thanks again...it does sound higher and more forward than the tranny tunnel next to me as the driver.

I need to remove my seat and redo one of the bolster's leather cover on the driver's seat though if I can get the back off I might just pull it independently. Have the red leather enroute and an industrial sewing machine which might make it possible without redoing the entire seats. Will see. A someday in 2013 list, possibly winter 2013.

[LancePearson]

Just went out and had the hood up so while I was there I checked the MAPS area rubber hoses and connections at the back of the engine while double checking the oil level after its recent change and three of the various ones took some light turns on the hose clamps with my screwdriver. Interesting setup and we'll see if that has a bearing on the noise as it is more nearly where I originally thought the sound came from. I thought it was a "whooshing" from some new water flow pipe or a valve that was reversed or something in my lt5 ignorance (which is still manifest, btw!).

There is a second dash area irritation with the ZR-1 and that is when driving while the targa top is off the glare off the dash board reflecting into the underside of the window which is right where your eyes look to drive. I had some soft boat indoor/outdoor black carpet so cut two pieces to fit then a piece of rug rubber non slip stuff and with my industrial sewing machine I used to use for my sailoat sails I sewed it together...end of glare if the wind doesn't fly it around. You can buy a dash rug for the whole dash to eliminate uv degradation but it's not that great a fit with the passenger side severe slope so I made one just for about half or at least what bothers my vision on a bright day with reflected glare. Dash is black and the carpet happened to be a perfect match in color and does not cover any venting at all.

[B17 Crew]

Originally Posted by LancePearson

B17, probably the original clutch though the ZF six speed tranny underneath the car has a blue metal tag on it saying "rebuilt to GM specifications" so it might be newer than that. Some early Z's had one version of the ZF and some later had another and they were differentiated by labels and from what I read, the later version had slightly different beveling on the gears. Original were what I'm told were "square cut" with no bevel and the later ones had a slight bevel. Square cuts, I'm told, will always be somewhat noisier but can stand a ton of force. I don't personally know what's in mine and am only repeating what I remember from reading other's posts other than what's on my tag on the tranny.

I am glad you enjoy the experiences of all of us as I know we all sure enjoy having them. I bought my Z in early Dec. n. of Atlanta and drove it home. It was in great shape but did not have an owners manual or maintenance records. I did have a Carfax and knew the brakes were serviced 7,000 miles before I got it, the fluids were fine and it drove well, clutch and tranny included though the "whooshing" sound was different for me and made me fret a little. When I got it home I had my shop go through and change ALL the fluids including tranny and rear end so I'd know their provenance and just last week had the serpentine belt and the pulley on the belt tensioner changed so I know their provenance at 45,000 miles. The belt was okay but the pulley needed changing but we put all new in regardless. All working well.

I have about 700 miles of driving it coming up to go to and from an all day Wazoo event at the Millers in Carlisle, Pa April 5,6,7 where I'll go west and hit the Blue Ridge Parkway and do about 50 miles of it then skip over to I 81 and go N. to Carlisle to watch the group tear into and replace a set of injectors on a Z, lunch, then see the Miller car collection, dinner with these terrific owners then home Sunday. The long, looping but scenic way around, weather permitting. If the weather is bad I'll go more directly. Then I may take it to VIR May 4,5 to watch some other Z's run the track in a TrackDaze event with my cameras if they are still going to do it, then May 15 head for Bowling Green and the gathering which is 646 miles each way.

I have a 76 with 100,000 miles on it and the clutch still works fine on it. The Z's is the smoothest clutch I've ever seen.....hydraulic instead of mechanical. Don't know what it's life will be but I suspect it depends on how they are used to some degree. I'm easy on clutches personally.

Lance

Hi, Lance.

I am under the same understanding as you regarding the “square cut” gears. From what I remember reading, the change helped reduce gear noise. Sounds like it is going to be one heck of a nice spring for you by having so much seat time in your Z; I can’t think of a better car to do a drive like that in. The option to drive a ’76 and a ’91 ZR-1 is pretty nice, they must be quite a contrast from one another!

B17 Crew

[B17 Crew]

Originally Posted by secondchance

Lance, B17 crew,

A couple of things - when transmission work is performed and transmission is dropped rubber boot under the console is often pulled down with the shifter unintentionally. After the transmission service as the car is being buttoned up most mechanics are too careless to install the rubber boot carefully and left side of the rubber boot is rarely secured over the lip on fiberglass body trans tunnel. Trying to slip the rubber boot over the lip is impossible fromthe top without almost total disassembly of seat, console side panel, etc... B17 crew noticing more noise with the ashtry door open is indicative of this. Solution would be removal of driver seat, console trims, console side panel to gain access to the left side of the rubber boot and slip the edge over the lip on the tunnel.

Another area to check is the map sensor hose. I had a situation where the map sensor hose was loose between the rubber boot and hard plastic line resulting in vacuum air leak. This also make a subtle loss of drivability and I emphasize subtle. In my case resealing of MAP hose cured the noise also.

This is great information, it makes perfect sense, thank you. If I meet up with it’s current owner, I will pass this info along to him. I sure wish the technicians would have addressed this though when they were getting things all back together. I sure did pay enough for it!

B17 Crew

[LancePearson]

B17,
Thanks...and, yes, the zr-1 is the best mpg vehicle I own. I haven't driven the 76 since just after I got the Z and then the contrast was astonishing...the clutch is very strong to push in the 76 and the power at about 230 hp in mine the way it's setup now is great for roads and fast enough but nothing, absolutely nothing like the punch of the Z or the TBSS with the 4:10 rear end and its stock 2008 ls2 engine of about 410 hp the way it's configured and set up for road racing by gm performance.

I love the 76 in appearance and it works fine except the other day when I tried to start it it would not fire though it turned over. I keep stabilizer in the gas so don't know what that is. I may end up selling it this summer to get my garage space back as the Z is so much more car though not the work of art that the 76 is. It is sculpture just sitting there with it's flannel cover on it.

I wish I had a four car garage right now....it snowed this morning lightly at 35 degrees and we will be about 18 degrees below normal here today...cooler than normal daily by at least 8 degrees for the next week or so continues...

Lance