Front end droning sound

Ok...so maybe I just didn't notice this the first month of ownership, or maybe it has just cropped up, but I just can't think of ANYTHING up front that would make this droning noise up front. The faster I go, the more audible it gets and it has nothing to do with engine speed. Can it possibly be just tire noise? I did a quick burst to about 150 on Thanksgiving and the thing was rock solid and I don't seem to remember hearing any excessive noise then....other than wind noise! It's a 4S, so I checked all the trim pieces up front and they are securely fastened. Any ideas? On a side note, am I the only one that has always thought that any S model was always free than any straight Carrera!? I just did some research and found that although by a measly 0.1 of a second in the 0-60 times, the S is actually slower! My guess with the upgraded brakes and wider stance, it would be much better on the track than a straight Carrera...but the 0-60 thing surprised me.

Did you check your front dif and wheel bearings?

My 03 Turbo started a droning noise that was so bad I drove from Wichita Falls to OKC to have the car looked at and the tech found the front tires were scrubbing a bit and making the noise. After he told me this and said you can feel the feathering sure enough when I felt the tire treads the feathering was there. He said no need to align now I could drive it home (2K miles). I did but as soon as I got home I got in for an alignment and the noise got better after the tires scrubbed in (so to speak) an adapted to the new and better alignment. Why was the alignment off? Well, very tired late one night on my drive east I pulled just a bit too far into the hotel parking space and the front tires nudged (I swear to God it was just a nudge) the edge of a raised sidewalk -- not even a curb -- and it felt like both hit at the same time so while started cursing myself for being so careless I was secretly thinking no harm done. No such link. The impact was enough for the alignment get off and the tire howling to build over the hundreds of miles I drove the day after and then the (nearly) same hundreds of miles I drove on the way back after my visit, during which I didn't drive the car 10 miles in several days. Really the noise was so bad I kept the car under the speed limit to avoid the worst of the noise. On the way to Wichita Falls and especially on the way back to OKC I had images of bad wheel bearings -- at least -- with possibly a bad front diff a real and scary possibility. 'course, a bad diff is always a possibility in your car's case, but I suspect that's probably not the case. More like tires and alignment than a wheel bearing. A front diff or something with the cardan shaft has to be very unlikely. Feel the tire tread on both front tires for any feathering. Feel the rear too. As an aside, be sure the tires are properly inflated. With cold weather upon us tire pressures have dropped and I bet many are driving around on under inflated tires. Also, it may not be any real problem. In one case - my Boxster with Pirelli tires -- the tires got so loud when they were due to be replaced that they masked a bad wheel bearing. After new tires then we could hear the wheel bearing. So, even if the alignment is ok the tires can still be quite noisy, naturally so from the wear and heat cycles. The Boxster front tires get like toy plastic wheels hard at around 40K miles.

After you've checked everything as Macster recommends, and if you still can't find the source of the noise, then you might consider the front differential. I'd start with a fluid change. If you notice any signs of leaking up front, then the differential bearing(s) are probably bad. You can have your differential rebuilt, but it's not cheap. It's cheaper than replacing it, but it will still be more than $3K. As for the 0-60 times, the C4S is heavier than the C2 and it uses the same engine. That explains the slower time. That being said, it was faster around the Nurburgring in Porsche's internal testing by ~4 seconds. The AWD, suspension, larger tires and brakes work very well together on the track.

Thanks Gents! I will check all this stuff out! Thanks for the suggestions!

BTW...the car only has 30k miles...would/should the diff or bearings be an issue this early?

Wheel bearings are a common problem - big rims, grippy tires can put a lot of stress on them.

+1 on the tire theory I just went through this exact same process. Coming from an Audi B5 I consider myself well versed in wheel bearing noise and was convinced it was a wheel/diff going bad. But it turned out to be the front tires scrubbing and wearing unevenly. Alignment done and then a switch to snows solved it

I agree mileage seems low for a mechanical problem. Can you post pics of the front tires?

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Diffs, wheel bearings, everything, can fail at any time. Generally, and thankfully, they do not fail at any time. After buying the Turbo I talked to the techs about front diff issues and they told me they have replaced a few under warranty. When I asked what the symptoms were why the diffs were deemed necessary to replace I was told because they made noise. At 30K miles while the car is still new (based on my classification that has a car new as long as its miles are under the 50K new car warranty miles limit) I would not necessarily go right to the front diff or even to a wheel bearing for the source of the noise. There are other more likely explanations: alignment as I touched upon; worn/aged (heat cycled) tires are two. I'd eliminate these possibilities before I started looking at the front diff or a wheel bearing.

Update...took the car to a local Porsche dealer and had a test drive with a mech there. He might have thought I was a little nuts. Checked tires and they are just fine. I don't think he denied that there was some noise up front, but he said it was so faint that it was just heard to tell what it was. Did some swerving at speed and the bearings or bushings weren't making any sounds. Chalked it up to road noise and said not to worry about it! I'm still going to keep an ear on it though.... Thanks for all of your input...I love this place!

You are probably just paranoid enough to join the "When Will My Engine Blow" sub-forum. Start building your shop, adding to your tool inventory, ordering service manuals, and setting up your accounts at Pelican, AA, etc.

KrazyK...yes! On all accounts! I'd kill for a lift in my garage. That being said, after my bi-monthly drive to work yesterday, I have decided to take it to an Indy mechanic next week when I get back home to take a gander at it...despite what the dealership mech said. I think the road we were traveling on during the test drive wasn't smooth enough for him to hear what I was hearing. Here is the best way to describe it. We all know what a late 90's Honda Civic sounds like with the huge tailpipe and loud exhaust! Well, from inside my car, it sounds like that guy is about 100 feet in front of my car doing about 50 miles an hour. I can feel a bit of a vibrational buzz in my steering wheel. All to begins happening at about 37mph and seems to be most pronounced around 52-57mph...actually gets less pronounced above that...maybe because engine noise becomes louder. Hoping its not the front diff, but the Indy mech comes highly reccommended...

Sounds exactly like my new-to-me C2. I've been out of town,but when I get home I need it looked at as well. Subscribed to what you find from your Indy.

Well, TS...that actually is encouraging to me! Makes me think it IS bad wheel bearings because in your C2, you don't have a front differential!! I will keep you posted!

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Definitely no diff in my case...I am suspect of tires. The noise is intolerable between 35-60 in my case. (Champion 19" wheels, Pilot Super Sport tires)

Diagnosis: front right wheel bearing is going bad. Indie mechanic needed about 30 seconds of road time to diagnose. Quoted $500-700 for the fix...am I nuts or is that high? I can't change a bike tire, so don't suggest I try to do it myself!

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Is that including the part(OEM?)? Seems fair but you might wanna shop around and get a couple more quotes as changing wheel bearings is nothing special and any mechanic can do it.

Yep...parts included...in fact he said parts were only a little over $125....

The real question is start to finish, how long does it take? Then you can multiply the hourly rate to see if he's in the ballpark. Last wheel bearing I changed was 35 years ago on a 914. Seems like it didn't take more than a few hours. 2003 Carrera 4S Speed Yellow / 1955 356 Continental 1500 Rust Red

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Based on my recollection from when I had the Boxster's rear wheel bearing done the estimate is ballparkish. The rear wheel bearing job cost a bit over $500. The parts cost was maybe $100. This was done at an indy so the labor rate was less than the dealer's though I do not know what the dealer charged at that time. Oh, time... that reminds me: This was done back in 2004 or 2005 time frame so whatever the price was then you can be sure it has gone up since then. Last, but not least, my info is the front bearing is harder to do than the rear bearing, and thus costs more money. Like I said the estimate/quote is ballparkish. You'll have to call around and try to get quotes/estimates so see if the estimate is reasonable for your area.

The OEM *** bearing at Pelican Parts is $53.75 , the hub tension flange nut is $10.75. 999-053-054-06-M34 Front Wheel Bearing (2 per car, sold individually) 996 Carrera 4S (2002-05), 996 Turbo (2001-05), Each Brand: *** Original Equipment Manufacturer at the time of the vehicle's assembly. After reading his story, kind of wish I would have done this while mine was apart for the front axles but the bearings felt fine. So I guess if you could DIY it would cost $64.50 instead of $500 - $700. That sucks.

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Your logic is flawed as you don't account for opportunity costs. If the guy makes $100-500 per hour, he would actually be losing money if he did it himself. Especially considering if he's never done it. It would take more time to research and do, as well as gather up all the tools needed, and even then you run the risk of f'in somethiing up rendering your car potentially useless adding more time/money/towing to nearest mechanic to fix it for you. While I'm a DIY'er myself, I've also been doing this stuff for over 20+ years. I understand not everyone would be willing to jump into something like this cold turkey.

Alp, youre really reaching for a chance to slam me but what you posted doesnt make sense. I posted: If he COULD do it. Also I doubt he works 24 hours a day 7 days a week. I dont skip work to do repairs I doubt he would either. Hence your second statement makes even less sense to me. I posted the parts cost for his information about price not to demand he do the work himself. Cmon, you really feel the need to nitpick my post?

Relax dude. I was just pointing out some reasons why everyone isn't inclined or looking to do a DIY on every little thing. If he was he'd be asking for potential advice on it. There's no need to inject the DIY perspective in every post and how you can save xxx amount of money and drilling it into them. When it comes to "luxury" goods like this, there's a good segment of people that would rather opt for convenience over time and such. Same reason why some people rather pay someone to mow the lawn. It's not that they can't do it as any monkey can but it's a matter of convenience and opportunity costs. Don't you gotta go and polish something btw? How's the engine coming along? You get that Snap-On pressure washing machine they had on sale recently?

Since the noise is faint, he can wait a little longer. Wheel bearings almost never totally fail in a short time. I had one slowly go for over a year, others lasted months before they were loud enough to change. He can also save money by removing the hub, buy the bearing and take the hub to a shop to have it replaced. I bet a shop wouldn't charge more than hour to press the bearing out and then the new one in.

^^^ That's another option but getting the hub off can be a b1tch(balljoints come to mind) for someone that doesn't have the proper technique or tools to do it. But yeah I can't imagine it would be more than $100 for labor if you did it this way.

Drone in my car was wheel bearings as well. Had the stealer fix it...under the warranty.