SLegacy99

My dad has an '06 330xi with the 6MT. We like the car, but it has always produced lots of road noise even at low speeds. My take of it is that its the run flat tires.

Now I just spoke with my dad and he was cruising down the highway and said the noise (which is kind of this whooshing, low toned noise) is getting worse. So bad that he has had to turn the radio up much higher than usual to hear it.

So am I correct in assuming that is the tires? Or could it be realted to the AWD (a longshot I realize), improper wear on the tires or something that Im just not think of?

This is our first BMW and its lease is up in just over a year.

Lexmex

Moved this to car chat.

picus

First bet is definitely the tires. As they wear they get louder; he might want to have them replaced or even look into non-rft's if the lack of a space doesn't worry him. I carry a fix a flat.

Check for cupping on the tires, I doubt it but you never know. RFT's are just straight up loud.

PhilipMSPT

iTrader: (5)

Road noise, especially if it's been increasing in volume, is most definately caused by the tires.

How many miles have the tires lasted? Run flats last for about 20k miles only (on average; it can be less if the car is driven "enthusiastically"...).

SLegacy99

Cars got 18k miles, so I guess that would be about right then.

picus

Yep. I'd definitely check the wear on the tires.

whoster

yeah, it's been noted that although BMW's use of run-flats reduce the need for a spare--but ride quality and general NVH from day-to-day use suffer quite a bit from the run-flats because they're so DANG HARD compared to regular tires. I mean...regular low-profile tires are thin enough as they are, but RUN FLAT low-profile tires are just....too much.

Threxx

Honestly I've been very impressed by the quietness of the 07 335i sedan I just got and it has the 18" wheels w/ sport suspension and run flat tires.

Now the RIDE quality took me by surprise. It rides so nicely until it hits a sharp bump and... well... let's just say my head has even hit the head liner a couple of times over bumps that never upset my Audi or Lexus very much.
When that happens the tires do make a loud thumping noise that sounds almost bad if you aren't used to it... like you hit something in the road like a giant pot hole. But if the road is smooth than the tires are smooth, and quiet... at least for now. As noted, almost all tires get louder as the tread wears down - especially run flats. And their tread life is far from great, too.
I remember when I first bought my GS400 it had the stock tires wore down pretty good and they were pretty loud - in fact when braking they got really loud - almost sounded like something was wrong with the brakes, but when I replaced the tires everything went back to serene and quiet again.

But yeah, in terms of noise I've been more impressed than I expected to be. I'd say as quiet if not quieter than the IS and TL I drove in terms of cruising noise, and definitely quieter than my Audi.

In fact the comparison test that Edmunds just published in the stats section shows the 335i as quieter at 70mph than any of the other models by a fairly significant margin.

picus

In the dry I believe it. The 335i is very well insulated from road noise. In the wet or on uneven roads the rft's cause quite a bit of uneeded noise (imo). On the 18" rft's my 335i was louder in the rain than my 2003 G35.

MGS4

I've seen some 3 series switch to michelin pilot sport A/S.

CK6Speed

iTrader: (1)

Definitely the tires making the noise. By the way, what year and what package came with the run flats? My 2002 330i Sports and Premium Package came with the regular staggered model 68 rims and a full sized matching alloy spare.

SLegacy99

Its a 2006, with the sport package and the premium package, 18 inch rims. I believe the sport package is where you get the run flats...which seems backwards to me. There is no spare in this car.

XenonES3

What kind of tires does your dad's 330xi have?

The OEM Bridgestone Turanza EL42's are notorious for cupping- leading to the noise. BMW will give you credit towards the purchase of new tires. I had my E90 330xi fitted with Continental ContiProContact SSR's and have not had any trouble since.

(by the way, BMW should never have used these tires to begin with. Check out the horrible ratings: http://www.tirerack.com/tires/tires....nSpeedRating=H

Good luck and let us know what happens!

SLegacy99

Im not sure what brand of tires they are actually. I'll ask him.

Thanks for the help guys.

picus

Almost every e90 I've worked on had Turanza or Potenza's (Potenza are stock, fwiw); both are kind of notorious for their road noise. He's right though, getting a credit towards Continentals would be awesome. They're much better tires.