996 Turbo - vibrations at high speed

[sealtt]

Bought a 996 turbo (2004) last week, it has 35k on the clock and seems to be in pretty much perfect condition. Test drove it and all seemed great, I was coming from a 2008 E92 M3 so it was notably stiffer.

However took it out on my 'private motorway' to test it out properly, at around 100mph I noticed it was vibrating a lot, fair amount of vibration coming through the wheel and inside the cabin juddering a bit.

I had the car taken to a garage and everything was balanced, aligned, new front tyres, etc. Took it out and it still did it. SO took it back to the dealer and they balanced wheels again, tested it and said it was fine, just how the car is - due to no weight over the front and stiff suspension.

So I just wanted to check in with some other owners / those with experience as to how it should be. I mean it is very noticeable at speed that it is vibrating a lot, though it does vary a lot with the road suggesting that it is just the surface, however the M3 was always perfectly stable and smooth at speed so just wanted to check.

Thanks
R

[sportsandclassic]

Hello,

Where in the UK are you ? I would take it in to a Porsche specialist/OPC and see what they think of it.

You may not be used to the car or there may infact be something wrong. Difficult to diagnose over the net.

Get it checked out, if near us then I will take a look FOC and give you my opinion as they should be fairly stable upto a point..

What mileage has the car done..? Did the people who balanced the car check that the wheels were not buckled or damaged ?

Mike

[mr pg]

Does it have wheel spacers fitted? I tried some last week, and they caused vibration. Now trying a different design, which I'll fit this weekend.

[phib]

Again difficult to be certain over the net but sounds like buckled / dented wheels.

Had this 3 times now and exactly the same symptoms.

Phib

[davek_964]

It's certainly not normal.

The only time I've had vibration was when my wheels were not balanced properly. Mine seems very sensitive to it, but is fine when they're correctly balanced.

[GreigM]

I'll add to the "not normal" camp - get them to remove the tyres, turn and re-fit them....balancing machines don't pick up everything and the tyre may be unbalanced at speed and you might eliminate it by turning the tyre.

[Daffy^Duck]

This is not normal. Mine was rock steady at 180 mph (and still pulling hard). I did however experience some very minor vibration a few times, when i was doing about 70 mph. I felt it thru the peddles for some reason. I knew i'd caught the plastic guard under the front of the car on my driveway. When i checked it was loose and bolts missing. Had a new one put on, and it was 100% again.

So i guess what i'm saying is that it may not necessarily be something major, but possibly related to the air flow etc...

HTH
DD

[6C4GTS]

Definately not normal to have vibrations that you worry about. It sometimes takes a few miles to get back into the way a 911 "talks" to you all the time if you have been driving something a bit more detached (SUV or big merc/volvo) but not to the extent you describe.

996 are very sensitive to balancing and being perfectly sat on the hub splines - more so than any car I have ever driven. When I had my wheels refurbed there was a few nanometres of coating too much on the rear face of the wheels and the car was almost undriveable above 65mph - but the wheels were perfectly balanced.

I would remove the wheels give the rear faces a good going over with sandpaper and check for dirt etc around the hub then try again - if not get the tyres refitted and balanced and try again.

Hope this helps.

[sealtt]

Thanks for the responses, well it does then sound as though there may be an issue... though I would have to take it to someone with experience to get that confirmed.

I am in Warwick, can anyone recommend a good place to go to around here?

Thanks

[surfymark]

If you are in Warwick then you must visit Center Gravity: http://www.centergravity.co.uk/

They will give you a full suspension tune up. They are know to be very good! I want to get my car over to them but they are a fair way from me.

HTH
M

[sealtt]

surfymark said:

If you are in Warwick then you must visit Center Gravity: http://www.centergravity.co.uk/

They will give you a full suspension tune up. They are know to be very good! I want to get my car over to them but they are a fair way from me.

HTH
M

Thanks, I sent them a message. Would just like to take it to someone with experience so they can go out in it and see if there actually is a problem or if I am just not used to the stiffness, so hopefully those guys would know.

[Tino]

I haven't got a TT, but a C4S, so a very similiar layout, and also had a vibration at above 90mph. Coincidentally I bought a set of refurbed wheels for the same price that mine would have cost to refurb. Swapped the rims onto my original tyres, and the vibration disappeared.
I has assumed that it was a trait of the car, but now, even at silly speeds its rock steady.

[monkfish2]

Do you know what type of machine they used for balancing? We have a Roadforce machine, which will get the roadforce as low as possible, and detect if the wheel or tyre is out of round and/or defective. We are near Milton Keynes if that helps?

[monthefish]

6C4GTS said:

It sometimes takes a few miles to get back into the way a 911 "talks" to you all the time if you have been driving something a bit more detached (SUV or big merc/volvo)

Totally. Feels quite weird/unnerving for the first few miles, until you realise it's just 'feedback overload'.

OP - I have a 996 Turbo and don't get any weird vibrations up to, and past, 100mph.

[zeb]

monthefish said:

6C4GTS said:

It sometimes takes a few miles to get back into the way a 911 "talks" to you all the time if you have been driving something a bit more detached (SUV or big merc/volvo)

Totally. Feels quite weird/unnerving for the first few miles, until you realise it's just 'feedback overload'.

OP - I have a 996 Turbo and don't get any weird vibrations up to, and past, 100mph.

its a good point that. My first 911 on the motorway was " what the hell" but to be honest you adapt and get used to it. Even now, my daily barge is a range rover and when i jump from that to the porker it still takes a little while to be re-accustomed so to speak

[sealtt]

Yes, that's why I am not sure if it just me and that I am not used to the car or if there is actually an issue.

Really need to go out in another one... any 996tt owners near Warwick!!!!!!!!!!!!!

[PhilRS]

Main reasons are likely to be:

Improperly balanced tyres
Uneven wear on the tyres (especially the front ones)
"Oval tyres" (can happen if one of them went flat then was repaired)
Bent wheel

[ism123]

I had this when I bought a used car. Blamed the balancing first, so did this, then it was less noticeable but still there at 120. It was then diagnosed as a bent wheel. I got a replacement from Jasmine and sold the bent one back to them

[guyvert1]

+1 on bent/buckled/flat spot alloy, opc/tyre shop should be able to see when they spin in up...

[sealtt]

yep, went to Autobahn Porsche near Coventry and they had a look and confirmed a damaged wheel. So will see if the dealer will replace it for me, if not then I suppose i'll go back to those guys and get it sorted there.