Weird vibration? - mostly with roof down.

[boxstSct]

Hi all,

Just joined on, after several months of searching and test driving Boxsters I finally picked up a 2005 S. During the test drives I didn't notice any problems driving with the top up or down and everything seemed pretty smooth and in line with 10 or so other Boxster models I tested.

After picking it up and driving it a few times now I notice that when the top is down and I hit about 70-75 the car starts to develop a vibration that you really feel in the steering wheel and when you look up at the drivers side frame of the front windshield it is vibrating as well.

When the top is up the ride is much smoother at this speed.

I can't remember if I noticed this in any of the other test drives mostly because of being so new to the car at first that I was just focused on everything else and then because of having dealers in the car with me and either not getting to go up on the highway for a long time or maybe just no being able to get up to speed.

So my question for you other Boxtser owners - Is this something common or a problem I am experiencing? Any suggestions on what it may be (ie: maybe wheel balance)?

Dealer is going to pick it up on Wednesday to replace a cracked battery cover they had put on order so hoping to have some ideas by then. It's not CPO but I've got a 6mo warranty from the place and they seem pretty knowledgable - so I am covered for any repair costs. Car had clean carfax and autocheck with no indicators or accidents of any kind.

[monie22]

Well I actually have a pretty bad steering wheel shake in my car too at 70-75 mph, but mine happens all the time with the roof up or down.

I have done a lot of reasearch and have had loads of people look at my car and none of them can see anything wrong.

The only thing some told me on the fourm, was that the guy who owed the car before me had it sitting around for a while before I bought it, and this could have let the tyre get "out of round". To be fair to me they look fine, but I dont really know what to look for. I have had all the wheels balanced too and this made no difference!!!!

Luckily, (I say) my tyres need to all be replaced now anyway, and I shall be doing this next week, so we'll see how I get on.

However going back to you, If the car has been parked up for quite some time then this could the answer?!?!?!?!

Not sure if it is any help, but just seems funny how I experincing the same symptons!!!!!

[boxstSct]

Please do let me know if the new tires make a difference.

The car has 26,000 miles on it so I don't think it ever sat in one place for too long during usage (could be wrong though of course) and at least more recently was traded in early in '09, bought by my dealer about 1 month later and I purchased a little more than one month after he got it in stock.

The tires have good tread so I won't need to replace them this year.

I'll post up what my guy after they have a look middle of the week.

[monie22]

Well as I say I may be completly wrong with my car and with yours.

I have to do my tyres now anyway, so I'll posted up the results of doing that next week and fingers crossed it make the difference!!!!

Also, yeah please do post up your findings too, would be interesting to know now whats causing your problem too!!!!!

[qikqbn]

problem too!!!!!

Hmmm... Sometimes our wide performance tires will "wobble" a bit when still cold in the morning. As they warm up, tire pressure

increases, and they flex a bit which may help the wobbling go a way a bit....

I have had several tires by now and always experience a little wobble when cold.

-balancing would be my first guess.

-check tire pressures

-maybe "flat spot" from very hard braking or skid... (abs should have prevented that though)

-new tires would be my next guess. Be sure to check "inside edge" tread wear.. Porsche sets

up the alignment to wear out inside edge faster.. (especially on rears)

everything may look fine on outside edge even though tread is very low on inside...

-Did the previous owner use "wheel spacers"??? if so, make sure they are flush against

the rotor. One time the screw that holds rotor in place was not screwed in tightly and flush.

so when the wheel spacer was installed on my car the rotor screw was out just enough

to throw things off and cause a horrible wobble. took me several wheel balances to figure

that one out...

alignment might not be a bad idea, although alignments should not cause major wheel vibrations.. so I was told,

but you never know.

best of luck,

Bill

Edited May 11, 2009 by qikqbn

[boxstSct]

So - problem solved.

Mechanic looked at the tires and there were balancing weights all over them and tape from where some had fallen off. He pulled off all the weights and balanced all 4 of the wheels. The ride is perfectly smooth now with top up or down.

Learned something new as well.

If you feel the vibration in the steering wheel means the front wheels are unbalanced.

If you feel the vibration in the seat of your pants means the rears are unbalanced.