Grinding noise after car has sat for a long period

[sjw]

Hi all, haven't been here in a looong time. I bought a "new" car about 6 months ago and the GTI has barely moved since then. Now when I do, it makes this sort of grinding noise. I assumed it's corrosion on the brakes, but they look ok.
 I fitted grooved brake discs, maybe the edges of the grooves are making the noise?

There is also a repetitive "duph" noise as well, I'm wondering if this could be flat spots on the tyres?

Any tips for either sound? For diagnosing?

Thanks

[SRGTD]

What’s the new car @swj? Any pictures?

Sorry, no idea what the grinding noise might be, but other forum members might be able to offer some suggestions. Is the noise there all the while or only under certain conditions - e.g. when braking, cornering, accelerating, or when performing other specific manoeuvres? Does the volume of the noise increase or decrease under certain conditions or with changes in speed of the vehicle?

As for the “duph” noise; I think you might be right with your suggestion that the tyres might have developed flat spots, especially if the car’s hardly been moved in six months. Are there any vibration or bumping sensations that can be felt through the steering wheel or seat? Does the frequency of the “duph” noise increase and decrease as you accelerate and slow down? If it is flat spotting, if it’s severe it’s sometimes possible to see the deformed / flattened section of the tyre.

Hope you’re able to find out what both noises are. When you do, please provide an update for the benefit of other forum members on the cause(s) and the fix(es).

[sjw]

I've bought a 997 Carrera S and I bloody love it



The grinding sound is pretty constant. I kind of need to take it out for a longer drive and see if it goes away, but at the same time don't want to make things worse

The duph noise increases with wheel speed. I suspect it is flat spots

Thanks for the response

[SRGTD]

I've bought a 997 Carrera S and I bloody love it

Wow! Looks fantastic . I can understand why you’ve hardly driven your GTI in the last 6 months.

Enjoy the Porsche.

[david25]

Hi all, haven't been here in a looong time. I bought a "new" car about 6 months ago and the GTI has barely moved since then. Now when I do, it makes this sort of grinding noise. I assumed it's corrosion on the brakes, but they look ok.
 I fitted grooved brake discs, maybe the edges of the grooves are making the noise?

There is also a repetitive "duph" noise as well, I'm wondering if this could be flat spots on the tyres?

Any tips for either sound? For diagnosing?

Thanks

1. Problem with the handbrake
2. Caliper stuck or sticky

Are the disc surfaces all clean or still rusty?

[MinchCS]

Take it for a good drive and do some heavy braking. Should fix both problems.
And, when you park it up again, leave it in gear with the handbrake off.