Bumpy Ride in Sport suspension mode

[Man In Black (MIB)]

Hi Guys,

Noticed recently that when my MY10 Golf R suspension setting is in Sport that there is a noticeably bumpier/shuddering ride. It's noticeable as turning the suspension onto comfort takes the bumpiness and shuddering away.

In sport mode it feels like the car has thrown a wheel weight. But I can't tell which wheel.

Anyone seen this before or have any ideas if it's the ACC mucking up or a shocker going?

Thanks.

[irossiter]

Sorry but what sort of question is that?? You put your car into Sport suspension mode and it rides more firmly and hits bumps harder! No way!

[MadWorm]

I have it in my R and agree it is "noticeably bumpier/shuddering" but hey, it's sports mode! irossiter is right.

If you're concerned it actually has a fault, take an ACC equipped demo for a ride to compare, or get your local VW service manager in it for a lap around the block, they'll be able to tell.

[Paul_R]

Wouldn't know. It's that long since I've used either sport or comfort. Normal is a pretty good compromise.
Would second the suggestion about asking the workshop.

Will be trying a non-ACC demo next time before deciding whether to bother or not. I have heard the technology has moved on so maybe it'll work better in the Mk 7.

[Man In Black (MIB)]

I have it in my R and agree it is "noticeably bumpier/shuddering" but hey, it's sports mode! irossiter is right.

If you're concerned it actually has a fault, take an ACC equipped demo for a ride to compare, or get your local VW service manager in it for a lap around the block, they'll be able to tell.

OK OK. My fault. Sorry. I haven’t explained it enough. Forget the word bumpier. Let’s start again.

RECENTLY the car has developed a suspension shudder on smooth road surfaces that it hasn't had before. Very oddly, this disappears when I put the car's ACC into Comfort mode. That's the odd thing that prompted me to ask the forum. Normally I'd just take it to a wheel and suspension specialist. However, the ACC Comfort mode fixing the suspension shuddering makes me think it’s more of a dealer issue. I’m just trying to save myself some time effort and money.

Now, I have been driving my Golf R for 3 years and am a big fan of the ACC. I use it a lot. So I know what it does and how it does it and what it feels like on the same roads I have been driving on for the past 3 years better than most thank you.

Given the recent VW action on recalls it may now be difficult to get the car in to a dealer to look at so I may have to go to a suspension specialist to look at.

I will report back so we can all share the enlightenment. Afterall, that's what this forum is for.

Thank you

[WhiteJames]

Try lowering your tyre pressure a couple of psi.
Otherwise the compression in the damper valving may be too worn & loose with extra relative rebound causing a constant patter on pimply coarse chip bitumen. Most VW's have this problem re:low speed secondary ride damping. Adding stiffer springs (marginally) may sort this problem out.
WJ.

[hoi polloi]

I'd still check the wheel balance first...

Maybe the apparent absence of shudder in Comfort mode is only the softer damping masking it better..

Regards,
- Anthony.

[Man In Black (MIB)]

Recently had the tyres rotated, balanced and all four corners aligned to no avail. Suspension shudder in Sport mode still exists and now also a bit in Normal mode too. Strangely, Comfort still takes it away ‘immediately’. When sport selected its back again ,‘immediately’.

I have noticed the effect is greatest when cold and in between 70-90km/h when warm. Someone suggested that this could be a diff oil issue.

I have the car booked in for a 90K dealer service soon so hopefully they can do some sort of diagnostic on the ACC to see if there is any fault.

Will report back.

[Man In Black (MIB)]

UPDATE, Have been told my left front is out of camber and its needs adjusting at the sub frame level before they will replace the faulty sensor on that corner which has set the suspension too high. This may be my issue.

Will report back on progress.

[Paul_R]

Wouldn't know. It's that long since I've used either sport or comfort. Normal is a pretty good compromise.
Would second the suggestion about asking the workshop.

Will be trying a non-ACC demo next time before deciding whether to bother or not. I have heard the technology has moved on so maybe it'll work better in the Mk 7.

Since my above opinion I've moved in with the in-laws for a few weeks while our house has some work done. I now have to commute 25kms each way along the Kiewa Valley Highway and have developed a whole new appreciation for comfort mode. On ****ty bumpy roads at 100ish kph it makes a big difference.

[Man In Black (MIB)]

UPDATE: Camber was actually fine. Both front electronic height sensors now replaced. No luck though.

Getting a local Porsche mechanic and suspension specialist to do a proper wheel balance to see what effect that has.

Problem most notable on smooth roads at about 80kph in Sport mode. If not wheels or suspension then could be a diff issue.

Will report back.

[Man In Black (MIB)]

Solved.

After much investigation (and new rear Shocks and rear diff end dampener) turns out it was a flat spotted tyre. Only one. That's why it didn't vibrate through the steering.

Flat spotted meant an up and down movement not a left right vibration (which you would normally feel through the steering). This is why the chassis control could control it in comfort but transferred the movement to the car's chassis in the less compliant sport mode. Effect was only felt around 80 and 100 and would go away when the tyres were hot.

Took it to a tyre/wheel expert in Mitchell in the ACT who pretty well diagnosed it from my description. We then ran them up on the balancing machine and one stood out (visually) as not being quite round.

No explanation for the flat spot. Could have been tyres where hot and I parked one tyre in cold water which changed its shape.

Anyway, real happy it's not the car's fault. Pretty annoyed with Jax at Fyshwick who I took it to 6moths ago for a balance and rotate and to find out what the problem might be. They should have seen the flat spot and reported it to me.

[Grah22]

Good to know it's fixed.
Strange you had no feel for the flat spot through the steering though...

[Man In Black (MIB)]

Shock absorbers were taking all the load so it wouldn't transfer through the steering. Left right movement/vibration would have been sent down the shaft and then to the wheel.

Certainly speaks volumes for the chassis control that it could hide it in comfort mode.

[kam]

takes a while to get a flat spot ?

as in, parked in the same spot for a couple weeks, not overnight...