Thats what the dealer said about my contiextreme a/s tires last week...I've been having vibration problems with my car lately (especially in the morning) and this could be the reason why...Even though the thread pattern of these tires are very agressive, I hate driving my car now, it feels like ****, and I'm regretting I ever bought continental tires....Are having flat spots in tires common, or is this a defect of some sorts, I have no real experience here with tires, so can someone educate me here? Also will this vibrating and rough ride smooth out a little over time?? It's been almost 600miles since I've had these POS tires..Even If I do exchange the tires for new ones, I still have to pay for mounting and balancing another $100 down the drain

 

Yes, all tires can develop flat spots if left long enough without driving. The more nylon in the casing or tread, the faster the problem can develop. Once this happens, the only cure is to get them hot enough to smooth things out, which typically means 8-10 miles at freeway speeds in moderate temps. Colder temps make the problem worse and longer-lasting.

In my experience, nothing makes a bigger difference in overall satisfaction with my cars than tires and their behavior. Over the years, with 50 cars since 1962, I've found that in general, Michelin makes the tires least likely to exhibit this problem, and the worst come from Pirelli. But each tire maker has tires in the line that are more or less subject to this phenomenon. Performance tires are usually the worst - more nylon in the belts, and less flexible sidewalls.

The previous generation S-Class sedans [introduced in 1992] had a problem with early examples developing serious vibrations at freeway speeds that would change in nature, but never go away. Later, these were traced to the use of Z-rated performance tires, which were fine for autobahn use and in fact necessary to run the car at 140 mph, but which were getting seriously flat-spotted in American driving conditions, and never getting hot enough to smooth out. MB solved the problem by specifying H-rated Michelin touring tires for US-bound S-sedans [and putting speed restricters on the drivetrain computers to keep the car below 130 mph], and modifying the front bushings on the S to make the problem less severe. The result was an easy solution, but a car which is still very sensitive to tire irregularities.

Some people are more sensitive than others to this problem; I am hyper, and so I take defensive measures by making sure the tires on our cars stay round. First, don't buy a car that really needs Z-rated tires; second, avoid ultra-low profile tires; third, if the car isn't going to be used regularly [we only take ours out a couple of times a week], I use cheap floor jacks to get the tires on all four corners off the ground. It only takes a couple of minutes before and after each use of the car, and while it makes me the "car nut who jacks up his car in the garage all the time", it also makes my '02 C240 as smooth as glass, even with Conti Touring CH95s [which have more nylon in them than Mich MXV4s - what I would have preferred as an OEM tire].

Generally, for a C-class sedan or coupe, I would use Michelin H-rated all-season touring tires, and I think you will find the car transformed from a smoothness point of view. On the other hand, if you MUST have all-out handling, you have no choice but to go with more performance-oriented rubber. But then you're not allowed to complain about flat-spotting or fast treadwear - those characteristics go with the territory. The "sport package" which is standard on your car specifies tires that I could not, and would not, live with. I would change them to an all-season Michelin, no more than H-rated [there are appropriately sized alternatives in the Michelin lineup], have them properly mounted and balanced by a dealer with a road-force balancing machine, and you will immediately notice the difference. This will cost on the order of $500-$600....not cheap, but less expensive than another car, assuming you are otherwise satisfied with the car. If you are being offered this kind of swap for the measly sum of $100, then you are getting off easy and should jump at the chance, assuming the replacements are really the right tires, of course. [The potential for this problem is one reason I avoid any car with a so-called "sports suspension" or "sports package" or "high-performance tire option"....and one reason we went with the C240 over the other alternatives in the lineup.]

 

That was a good reply, but my question is, will this vibration go away anytime soon? man, I wish I still had my Pilot Sports, didn't realize how good I had it with those tires...Doug you out there, I want to buy them back jk

Anyway, I have the option of exchanging them for the same set, anyone else experiencing this with the Contiextremes?

 

You mention up top that its only the left side. This really doesn't make any sense. Sorry. Something smells here if that is what the stealer told you. $0.02

 

Hmmm, I've been using V-rated Continentals and Pirellis for more than 20 years and have never had a problem with flat spots. My current car has V-rated Pirelli P-6000's (summer) and may sit for more than a week w/o being driven. The only vehicle in my garage with a flat spot problem is my golf cart

In any case, a short drive should get rid of the flat spots.

Maybe the problem is a warped rotor.

 

Once flat spots have developed, there is nothing for it but to try the following [if this doesn't work, the only solution is to throw them away]:

-Inflate the tires to the max allowed on the sidewall, typically in the 44 psi range
-Run them for at least an hour on the freeway, preferably at ambient temps over 50F
-Jack the car up, with all four wheels off the ground, and spin the wheels individually, checking for vertical runout [lack of roundness]. Any variation over 1 mm is grounds to reject the tire/wheel combo...any modern chassis will transmit vibrations if the total runout exceeds 1-1.5 mm.

I'll repeat that some people are not sensitive to this problem, so the fact that you've never experienced it doesn't mean your tires are all round. And, I'll repeat that individual tire companies make individual tire models that are more or LESS susceptible to this problem.

With Michelin MXV4s, I have been able to leave a car sitting literally for weeks, and have the tires smooth out after less than 10 miles of freeway driving [this does NOT mean I couldn't feel some shaking initially - just that it doesn't last, and it takes many days for the phenomenon to show up]. With some Pirellis [P4s in the old days], even sitting overnight in cold temps would cause them to get lumpy, and on our '81 300SD, they literally never got smooth again - I threw them in the trash in favor of Mich MXVs, which transformed the car.

Our '89 260E came with V-rated MXV4s, and these would get lumpy overnight, but always smooth out after less than 2-3 miles on the freeway to work.

You'll hear from some folks [see above] that they have never experienced the problem, so doubt the diagnosis. I have, and I don't. Yes, the dealer is probably wrong that only the left side has a problem, but it IS within my experience that even with new tires, one or more of them COME FROM THE FACTORY with vertical runout problems. This could be the case with this set of Contis.

I've already told you that I would go back to the Michelins in a heartbeat...I doubt seriously if any other solution is going to be satisfactory.

 

Got 4 of them on 18x8 wheels from tires.com. They came mounted and balanced.

Installed them on the car myself. I drove the car and from 55mph onward there was MAJOR vibration. Called tires.com and they said find a place that does road force balancing and do it and we'll pay for it.

I searched the Hunter website for places that have the GSP7000 (maybe 9000) balancer near me and had it done. 3 out of 4 tires were out of round. The GSP7000 allows the installer to rotate the tire on the rim to match the lows of the tire with the highs of the rim to even out the balancing. This worked on 2 of the out of round tires. The 3rd was so bad that even with the rotation, it was still WAY out of round. Called tires.com and they shipped me a new Conti immediately. Just had it installed this morning.

As a sidenote, even the good Contis develop flat spots overnight and they smooth out after 5 or so miles on the highway.



CZ

 

I've still got'em, but danged if the price didn't go up!

If the tires are flattening out at night, I don't know if there's a lot you can do for it. If the tires are molded out-of-round, then you may have one possibility:

From my old racing days I do know that there are some shops that can 'true' tires. That is - they have a sharp spinning blade mounted above an axle. They mount your wheel on the axle, spin the tire, and the blade cuts down any 'high' places, until the tire is perfectly round.

You may need to find a shop that shaves tires for road racers or autocrossers, but there is probably one up your way.

PS: If you've ever had to drive the Michelins in the snow, you would long for the 'rough' ride of the Contis!

 

My Pirrellis would do it while parked in the parking lot at work for 4 hours. 2 miles later it was gone. Soft rubber will do that in the old weather. In the summer and other warmer months they were fine, only real cold days. Then again it could be the darn road in my case, since I live in PA, where there isn't a smooth road to be found. If they find it, it will be immediately turned into a construction zone... My new Conti-Extremes do not do this. Well, they did it once and it was cold as hell that day. Remember each tire pad is holding up about 750-900 pounds. These are heavy cars and it is not too hard to develop a flat spot in the soft rubber on a cold day. The rubber is stiffer in the cold, so when you park that car with the nice warm tires and then the tire coold rapidly. What do you expect.... Although yours sound to be more than just parking flat spotting....

 

Last month I ordered two Conti's from tirerack and had them installed. Car had a continuous pull to the right. Gave it to the dealer to fix, and they tried for three weeks. Finally pulled a set of wheels from a new model and put them on my car and pull went away. I called Tirerack and explained to them that the dealer thought
the tires were of a bad mold. Tirerack did not hesitate at all and shipped me two new Conti's. Got them yesterday and the dealer had them installed today, car does not pull any longer. Sounds to me like Conti is having some quality control issues of late. These were the factory spec. sport contacts 245-45-17. Gotta hand it to the Service manager, he went the extra mile and did not charge me a penny over what was spent the first time last month.

 

Well, what I did last night to help improve the conti's rough ride was to increase the tire pressure slightly to compensate for the flat areas....these tires are not perfect, but aside from the rough ride they are indeed good tires, contrary to what I posted before...Today the problem was less noticable, which is enough for me to bear.....I've been paying too much attention to it latley and I just say move on with life and realize you get what you pay for...Next time Michelins all the way, never had any issues with them

 

Just be careful with the high Pressure. You can certainally wear out the center tread unevenly from the outside by overinflation.

 

Are those 18s or 17s?


CZ

 

The Hunter web page is at:
http://128.242.141.111/pub/search/findgsp9700.cfm

 

And what I perceive to be a "flap-flap-flap" noise which gets more frequent with speed so it must be a flat spot. I have to take it back to the balancer guy since he said that al 4 tires are now in the low teens in road force.


CZ

 

Well, I thought increasing the air pressure might help solve this problem, but it's back....After almost 800 miles, I would think this problem would go away....The "flap-flap-flap" feel is what I am getting as well....frustrating...does this GSP9700 machine really work?

 

I have had the Conti Extreme Contacts (OEM size) also, for about 3 weeks now. I am feeling some roughness when I start out. After putting some heat in the tires, it goes away. I just put about 1600 miles on them with a round trip from Atlanta to Maryland, and other than the roughness/vibration when I first start out, they were fine. I ran between 80-85 mph most of the way, and while they have more road feel than the Michelin Pilot Sports, I am pleased with them. I am going to go back to my tire dealer and have them check the tires, buy my guess is this is normal for this tire.

 

But it's still there. After the GSP9700 balancing I thought the vibration was gone but it was just diminished enough so that I didn't notice it. Yesterday I drove over 50 miles and then "flap flap" was back at speeds of 65mph and over. It did not go away at all even though the tires must have warmed up during the long ride. I think Contis just suck. I am going to go back to the GSP9700 guy to see if he has a clue.


CZ

 

I think the Conti's do just suck...I was so pumped when I first got them because they are indeed good in snow...However, this issue is very annoying....But I have learned a couple of things -

1. Michelins are the best, period.

2. Don't buy a sport sedan with low profile wheels if you must drive in snow/ice/slush causing you to switch wheels...this just doesn't seem worth it...to me now anyway

 

Pete,
There is hope yet. I took my C230 back to NTB this afternoon. They dimounted and rotated three of the tires 180 degrees, and rebalanced all 4. I no longer have a vibration. I ran all the way to 125 mph without a hitch. You will need to find a tire shop willing to work with you. I thought I remember you bought them from TireRack. Someone above had great success with getting replacement tires from them, but that is not the normal response from them. And most tire shops don't want to deal with you if you used TireRack. If you bought them locally, take them back and have them make good on them. I have had many sets of Continentals over the 35 years I have been driving, and never had a problem with any of them.

As far a Michelins... they have had their troubles too. My Mustang GT went through 7 tires before I found one that was true enough to eliminate the vibration.

Dont give up on the Conti's yet. You are bound to get some more snow in the next few weeks that will make you glad you removed your Michelin Sports.
Steve

 

Hey Steve, I actually got the tires through my step dad from a wholesaler (he owns a body shop and can get a little discount)...He's driven the car several times, and he says he can't detect the problem really and that I'm paranoid...I disagree with him, but adding more air pressure did help the problem...But the car almost wobbles when it's really cold outside for about 10 miles until it gets smoothed out...I had it road forced balanced at the MB dealer I bought the car from, and that hasn't really helped...I am hesitant to get replacement tires b/c this problem might exist with them also, plus more money to balance, and my 30 day free trial is 15 days over...I called the customer rep at Continental and he said it was my car and not the tires, so basically I'm not going to fight it and invest more money and time which is a shame, b/c the car doesnt seem the same to me anymore, but that's life I guess...My last hope is that when the weather warms up I will experience this problem less

 

If your car was smooth on the OEM tires, then it cannot be the car. Sounds like you got a rookie Customer Service rep. that doesn't want to admit his product might have a problem. I will admit, while I don't have a problem with the Conti's, they have more roughness to them than the Michelin Pilot Sports had. I relate it to, the Michelins were like driving over glass, and the Contis are like driving on glass with small rocks imbedded in it.

Even though I live in Atlanta, and we really don't get too much winter weather, I do enough driving up to the DC area and in the mountains of Tennessee, I felt leaving the Pilots on was just pressing my luck.

 

I had a vibration problem after the dealer installed steel rims and snow tires. Two return trips to the dealer with them rotating, re-balancing, and adjusting tire pressures failed to correct the problem.

During the last visit I noticed that they were tightening the wheel bolts using the impact wrench.

When I got home I re-torqued all of the bolts by hand using a torque wrench. All of the bolts installed with the impact wrench were far too tight.

Vibration completly gone once the wheel bolts were tightened properly.