VX Road Noise. What To Do?

[robmcg]

All,

I have a 2001 VX Calais International at 96K 5.7 LS1 and 4L60E all standard, no apparent faults. 17" factory 6-spokes.

An experienced mechanic here in Canterbury called it a 'minter', but he builds 9-sec NO2 V8s and races A-Grade stocks... so what would he know? <g>

It's quite noisy on open roads coarse chip, but noisier than I would have thought reasonable. I am 56 and used to build Jags and Minis, and it sure ain't as good as a 70's XJ6. Or maybe I listen too often to classical music...?

Had a tyre rep from GT Radials take a drive, with Champiro 328s then HPZs before/after, and also, we cannot find fault with front bearings, rubbers, driveshaft, or anything. He called the noise 'acceptable' and thought it was the uni-directional nature of 235/45s. He drove on 50-100km/hr areas but in fairly heavy traffic. Good on him he didn't charge. The new HPZs might be a tad quieter at lower speeds.

I'm thinking the noise is a bass roar from the transmission tunnel area, and bass is hard to track. I'd say that it's a mix of tyre and poor soundproofing...

There is no record of any work from the factory dealerships from new except a rear gearbox seal at 70,000kms. The car is very silent at say 60-70km/hr on smooth roads, so am I just being fussy? The box works fine. The driveshaft is good to all visual and 'feel' checks. There is no actual vibration in the car at any speed, and the LS1 is a joy.

The exhaust in inaudible... but the tyre-noise is too much. No sign of alignment/steering issues.

Should I trade it for a 540i?

[Squish]

What tyre pressure are you running? This can change the amount of noise the tyres make.

Having driven a 2002 540 they are not much quiter inside, but i would still like to own one.

[robmcg]

34-33 f-r cold.

Tyre seller put about 36-37lb all round, cold. My guage is fairly close.

Thanks for the reply.

Rob


What tyre pressure are you running? This can change the amount of noise the tyres make.

Having driven a 2002 540 they are not much quiter inside, but i would still like to own one.

I don't think I'm all that fussy about noise generally. Maybe I am getting old and crabid.

I was running the Champiro 328s at 30lbs and the Potenza GIIIs before that the same, 30lbs., and they were also noisy-as.

That's why I have posted here. It cannot be normal.

I've driven the same Canterbury roads for ten years. My VR Calais 5.0 with FE2 was quieter, as was my standard VS Calais, and my VT SS with FE2 was about the same as this VX, except it was a bit tighter and rattled.

The VX International 'roars' on coase chip.

Rob

[Jargle]

they should be 36psi cold, and even classical music sounds good loud or so I'm told.

on the other hand an exhaust upgrade maybe due:p

[jerrel]

i also havnt been happy with the ammount of road noise in my car. i have had all wheels rebalance, and alligned.
i put it down to them being high performance (y speed rating) and after reading this, maybe the presure (40psi all round, warm)

[r8ls1]

It's the low profile tyres, drive it on 15" balloons like those 70's things had and they feel like a hovercraft.

[robmcg]

they should be 36psi cold, and even classical music sounds good loud or so I'm told.

on the other hand an exhaust upgrade maybe due:p

Thanks. Could be that a nice exhaust could make the car more enjoyable.

I'll run 34-ish lbs for awhile... I have a set of 15" steels with Yokohama S306s which are fairly quiet, but they don't do much for handling or grip.. or looks.... if the noise of the 235/45s gets to me.


they should be 36psi cold, and even classical music sounds good loud or so I'm told.

on the other hand an exhaust upgrade maybe due:p

Why would that be right and the factory 29psi be wrong.. the factory saying 34psi for 160km/hr+ ...I think they had RE040 Yokohamas which are similar to many 235/45 ZR 94-7W including these Champiros..?

Maybe the car is just simply noisy? I didn't see it mentioned in contemporary road tests.

[Squish]

Why would that be right and the factory 29psi be wrong.. the factory saying 34psi for 160km/hr+ ...I think they had RE040 Yokohamas which are similar to many 235/45 ZR 94-7W including these Champiros..?

Maybe the car is just simply noisy? I didn't see it mentioned in contemporary road tests.

While 29psi isn't wrong, it is a comprimise. When they build the car they have to balance handling and comfort. I know when i run my tyres at 29psi they make a bit more noise than they do at higher pressure. Try bumping them up a little and see if it makes and change. Other than that maybe it's the tyres. I have neaver driven on them but maybe they are nosiy.

The idea of the higher pressure is to change how much of the tyre is on the road, a higher pressure will give you a smaller contact patch and with a bit of luck a quiter ride.

If that fails i would be looking at some diffrent tyres, if that is an option.
Good luck with it.
Adam.

[robmcg]

If that fails i would be looking at some diffrent tyres, if that is an option.
Good luck with it.
Adam.

Thanks. The car came with 1/2-worn Potenza GIIIs [very noisy'] then I fitted new Champiro 328s [slightly better], then replaced one front hub [just audible with stethescope] , [slightly better] then changed to Champiro HPZs [slightly better]... and now I just live with it!

It's a very very quiet car on good ashpalt now... like a hybrid! But on coarse-chip rural sealed highways, well it ain't one of GM's finest acoustic achievements.

Of course I have to trade the looks of the 17s with the amount of noise, but I want my cake and eat it too... or I might think about more soundproofing as a project sometime.

Rob [Canterbury]