Incendiary

My mom has a 2006 S350 that was hardly driven for the first 1-2 years (we got it in late 2005). However, for the past 2 years, my mom has been driving it regularly / daily. As of about, oh, less than a year ago, we noticed that over 70+ mph, the car will shake periodically on the highway. She brought it into the dealership today, since it's still under warranty, and was told that the tires are flatspotted and all 4 need to be replaced.

I call horse manure. If anything, I'd think it just needs a rebalancing, and at very worst, realignment.

Any opinions? Can the dealership possibly be right? Is flat spotting still an issue with modern tires?

notoriousALE

balance and alignment.

vmystikilv

It is possible. I had an 850i BMW that the same thing happen to. But, the tires were old as dirt and I had let it sit for 6 months. When I started driving it again it wasnt till I got new tires that the road turbulance stopped. I let cars sit before and this didnt happen. Out of all the cars I ever had I guess it was the age of the tires combined with the fact of months of not driving.

~CL500~

Try a balancing first to see if it works. Next step would be to replace the tires. Flat spots can happen for sure.

m4xm1l10n

Agreed , and also lack of use the more are the chances to have a flat spot tires . i would just get new tires .

Incendiary

If it were flat spotted, wouldn't there be a shaky feeling at all speeds, both low and high? Not just at 70+ mph? And why wouldn't the problem have manifested itself a couple years ago, rather than now that it's driven daily?

Car has 16k miles, just FYI.

ebolick

Do a search, i know there is a lot of topics on this. I had the problem also and it ended up being a tierod or something i forgot it was ahile ago.

But the dealer at first told me it was the tires, then the alignment. and then i remember reading this is a common problem that happens to these cars.

Good luck.

Incendiary

Okay, so I'm searching for the tie rod? That's the common issue, you mean? Or the shaking is a common issue?

ebolick

Shaking is a common issiue, when going over 70.

ebolick

This may help

https://mbworld.org/forums/s-class-w...ons-70mph.html

ebolick

Come to think of it i think it was my control arms that time. there are known to go out.

Incendiary

Thanks for the link. Looks like that thread is mainly dealing with staggered wheel sizes in 4MATIC / AWD cars, though, which does not pertain to me.

~CL500~

The flat spots may have thrown off the balance slightly, which would cause a vibration to occur at speed. I experienced a moderate vibration around that same speed and the balancing fixed it. It's a small cost to pay to get it right and your tires should be properly balanced anyway.

~CL500~

It's pretty easy to check your tie rod ends for play before spending $$$ to replace them. Get the front end off the ground, hold the front wheels at 9 and 3 o'clock positions and try to move it side-to-side. If there's play, then your tie rod end is bad on that side.

Incendiary

Well, both the dealership and NTB have said the tires are flat spotted. Dealer said to replace all four, but NTB said just the rears are problematic and balanced the fronts, so I guess I'll be ordering two Pirelli tires for the rears tonight...

Thanks for the help, all.

ohlord

tires.Order your tires,I hope you are not letting the dealer sell them to you.
Tirerack also for good prices.

Incendiary

Tirerack all the way.

DrJfrmLA

Tires. It may not be flat-spotting, it may be tread separation from age. Tires that sit do flat-spot. If my math is right, the tires are at least 4 years old assuming they were new when they were put on the car. Depending on ozone levels and other pollutants (Manhattan isn't tbe cleanest air in the world), the tires could literally rot on the rims in that time. Not being driven (and not being heated up as a result) speeds the process. My mother drove every day, but only in town. When she died the tires on her car had 80% of the tread left, but the first time I took the car out on the highway, it was like riding a washboard. The tires were about 4 years old and they were separated and completely unsafe for highway travel. We got a mileage allowance on new tires, but that fixed the problem. It felt like a bent wheel, warped brake rotor, tires out of balance, all the front end stuff loose and wandering--it was just old tires. I'd try that before I started replacing front end parts. Good luck.