Vibration while driving at certain speeds

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Aquadelic
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Vibration while driving at certain speeds

Post by Aquadelic » Tue Jul 23, 2019 3:23 am

Hi, hope your sciroccos are treating you well.

I've been scanning this forum and the VW vortex forum to try to diagnose a problem I'm having with my Rocco.

At slow speeds she drives ace, no noise, vibration or anything. Spot on. Or, the issue is so quiet I can't tell at low speeds..
At 80-100 km/h theres a noticeable vibration. It has a "frequency" so I think it's based on the wheels. I noticed my passenger side brake dust shield rattles when I close any door and it didn't used to. As for road noise, I noticed it felt like I transitioned from fresh paved road back to normal road - that kind if vibration, except the road quality didn't change. If that makes sense. Doesn't seem to change based on RPM or with the clutch pedal pressed/neutral.

What I've Done:
1) I jacked the car up and checked both front wheels at 12 and 6 o'clock. Zero play. Slight play left to right (3 and 9 oclock), perhaps 1-2mm play. Steering wheel didn't seem to be turning when I looked while shaking the tires/wheels left to right.
2) Tire pressures are equal all round. One tire is new, on the rear. The other 3 are half worn and aged - close to 10 years if i recall correct. I originally replaced the front two, then proceeded to nail a curb on passenger side and blew out that tire and the rim is currently being repaired. Then I swapped the good wheel to the back, so that I'd have two equal tires on the front. Before swapping, I had a bad steering veer - car now drives poker straight.
3) Steering wheel does not shake. Car does not veer, stays straight. Everything is kosher except this slight noise and vibration as if I'm on aslightly rougher road.
4) Only occurs 80-100km/h. I think it does it at higher speeds but the road noise easily drowns it out. Can't notice at low speeds.
5) Previous owner went through almost all suspension parts except the tie rod assemblies.

God I love these cars, regardless of what they do to me. One year into ownership, and I absolutely love it.

Any help is appreciated. If I missed a similar topic that covers this, I apologize. Hate to be redundant but I hate having my Rocco sit still even more. Thanks in advance,

Aquadelic


1987 Scirocco 2.0 16V
1972 Ford Capri

GT_II
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Re: Vibration while driving at certain speeds

Post by GT_II » Tue Jul 23, 2019 11:37 am

Have you checked the wheels are balanced? You'd normally feel vibration at the steering wheel if they were out. Other than that, you're maybe looking at a wheel bearing or driveshaft problem.

If you damaged a wheel by hitting a kerb, then progressive wheel bearing damage is quite likely to follow. If so, get the bearing replaced before the vibration causes secondary wear to suspension components. Try spinning the front wheels by hand to feel any roughness or noise in the bearing.



chopperoli
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Re: Vibration while driving at certain speeds

Post by chopperoli » Wed Jul 24, 2019 10:00 am

Check your strut top bearings too, the rubber often pushes through then it's metal on metal contact inside, that would transmit more noise



mark1gls
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Re: Vibration while driving at certain speeds

Post by mark1gls » Sat Jul 27, 2019 10:17 pm

If you can try another set of wheels and then you can rule wheel balancing etc out....


Mk1 78 Scirocco GLS 1.6 FR, weekend toy.
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kidcrewbob
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Re: Vibration while driving at certain speeds

Post by kidcrewbob » Sun Jul 28, 2019 10:31 am

If you can’t feel it in the steering or upon braking then wheel bearing would be my first check - I have a similar rhythmic clicking come rumbling esp noticeable at higher speeds and have 2new bearings to fit when the bloody rain stops!!



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Aquadelic
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Re: Vibration while driving at certain speeds

Post by Aquadelic » Sat Aug 03, 2019 7:23 pm

chopperoli wrote:
Wed Jul 24, 2019 10:00 am
Check your strut top bearings too, the rubber often pushes through then it's metal on metal contact inside, that would transmit more noise
Aha! The top mounts look terrible, rubber is split and rough. Luckily I hoarded some new ones last summer :-D I've replaced the passenger side, soon to do the driver's side today. It's reduced the vibration a fair bit. Might rule out the wheel bearing for now.

Did the alignment with a tape measure and a second set of hands. Car still veers, on accel pulls left and when you let off it corrects itself. Picked up new control arms and will replace those too while I'm at it. I have new rubber to throw on, but a bit reluctant since I don't want to wear the tires oddly if the suspension isn't right.

Hey what gives with inner tie rod assemblies? I have P/S. Bentley makes it out to be a royal in the arse. I have new inner/outer assemblies to go on but it looks like a pain.


1987 Scirocco 2.0 16V
1972 Ford Capri