Vibration/'lumpiness' - polybush to blame?

Hi all - picked up a cheapish 2005 2.5T geartronic V70 recently - only done 85k. It goes well but is a bit tiring to drive as the front end doesn't seem very smooth - there's a vibration felt when I place a foot lightly on the brake pedal without pressing down, the car is twitchy (and vibrates more at about 75mph) and a bit lumpy on changing down to a stop. It also vibrates at a stop in drive but not so much in neutral. There's little/no vibration through the steering wheel.

I had an indy look at it and they said all the lower engine mounts are fine but the top was split so they changed that but it's made things worse if anything.

They noticed the front wishbones are polybushed and suggested changing them to Volvo ones - is this likely to improve it and is there anything else to look at?

It's also using a fair amount of oil - but they couldn't see any leaks (bone dry they said). Is this usual?

Thanks

Jack

Driveshaft bolts tight?

oil usage is normal... how much are you talking?

poly wishbone give a little more cabin noise - that's the only negative side effect.

as Mr. 99 said, check the hub/driveshaft bolts. your gearbox is probably worth a flush (guessing it's the semi auto gaytronic) and a full suspension geometry alignment wouldn't be a bad idea. it might even be a knackered tyre. sounds like there's possibly more than one issue here.


welcome aboard by the way.

find it depend on what oil your using....
i would get the tracking done first. the polys should be fine. ovlov ones are ££££e
your tyres could be out of shape? trackends etc.

Quote:

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Originally Posted by Jack London

They noticed the front wishbones are polybushed and suggested changing them to Volvo ones - is this likely to improve it and is there anything else to look at?

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Poly wishbone bushes shouldn't have any effect on vibration, I didn't notice any. Don't waste your money fitting new wishbones.

As daft as it sounds it is possible to fit wishbones upside down which obviously causes all manner of geometry issues.

Check the gear box to subframe bushes are OK, they don't last very long if another bush has failed for a while.

Thanks all

- will get the driveshaft bolts checked although there are no clunks
- tracking too (but there's no uneven tyre wear)
- Volvo indy checked all the bushes/suspension and couldn't see anything other than the top mount - is it worth changing that gearbox/subframe bit anyway?
- don't know what oil is in it - indy serviced it initially and it then was right at the low end after about 3000 miles and the oil light came on - recently it's lost about three bars on the stick after round trips to Manchester and Coventry from London plus daily 10 mile urban use - about 1200 miles. I've topped it up with 5w/30 synthetic.

It does drive better over very smooth road but that's a rarity and it does vibrate in drive at a stop. I'd like to get it more like it was when it left the factory and the polybushing is obviously the only non Volvo mod. Is there anyone else in north/east London who knows these cars - maybe i should get a second opinion.

As has already been said polybushing won't cause any adverse vibration, heck on my car there's not even any extra cabin noise.

its pretty subjective graham, there definately is an increase but you get used to it.

on a p2 it is worse than other models even ona petrol. i find that it is worst on an auto when you are stationary but engage drive. - this is because the revs drop resonance to the critical frequency where it is most likely to happen.

Quote:

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Originally Posted by partsforvolvos.com

its pretty subjective graham, there definately is an increase but you get used to it.

on a p2 it is worse than other models even ona petrol. i find that it is worst on an auto when you are stationary but engage drive. - this is because the revs drop resonance to the critical frequency where it is most likely to happen.

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650-675 rpm usually ;)

exactly- right where it is with a/c on when compressor kicks in ......

but then, poly wishbones alone won't make any difference to engine/transmission vibration or noise.

i wouldnt have thought so with wishbones only.
- is the new top mount a polybush or a rubber one ?

which ever it is, i would have thought it will be transferring more noise than the old split one .

Thanks again for the info. Car is going to the Volvo indy next week for a couple of other things - can you spell out exactly what I can ask them to look at regarding this vibration issue? I'm going to ask for a quote on replacing the wishbones with Volvo spec - what would be a guide price for this?

thanks

I would seriously consider leaving the wishbones as they are mate - they won't be your problem.

Get them to look at the gearbox fluid and flush if it's not 100%

All the engine mounts and tranny mounts and driveshafts/CV joints.