strange noise at motorway speeds

[dave7268]

Okay, so I went for a run with the parents on Thursday which involved and hour and an half drive on the motorway each way.

We were travelling at a steady 70, dropping down to 50 at places due to speed restrictions and during the whole trip we could all hear a noise that we were not able to pinpoint where it was coming from.

It was a continuous sound which was kinda like an aircraft engine noise when cruising except about every 10 seconds the sound dipped in pitch for a moment.

No windows were open, door seals are all perfect and it didn't really sound like a wind noise to be honest. Aircon was on for the return journey but off on the outbound journey.

Jacked the car up today and there is no free play at all in the wheels. Both real wheels when spinning them made a rubbing sound every rotation (is this normal?). Front wheels where very difficult to spin and required a lot of effort (is this usual for a DSG vehicle? (car was in neutral)).

Anyone else come across a similar strange noise driving over 50mph? Or any thoughts before I get the car booked in for the dealers to look at as it is still under warranty?

TIA 

[C3PO]

checked your tyres? uneven tyre wear quite common.

[Raffe]

Sounds remarkably like the inner edges of your rear tyres have worn badly with the 'sawtooth' pattern.

If you run your finger around the circumference of the inner edge of your rear tyres they will fell bumpy if its done this.

Very common on FWD cars with low profile tyres, I've had my last 4 cars do it with Toyo/Goodyear/Bridgestone tyres.

[dubber36]

I'd go with tyre wear too. The change in sound would be to do with differing road surfaces/construction.

You'll also need to get your suspension geometry checked and corrected AFTER fitting new tyres. This needs to be done properly. The dealers will charge around £100 and give you a 12 month warranty on the job. It is normal to have to pay for this if the car is over 6 months old, as they will say (and you can't prove) that it hasn't been caused by some sort of impact.

[dave7268]

Thanks guys.

Just checked both rear tyres and they are as you describe with a saw-tooth pattern on the inner edges.  Now got some new tyres on order.

Do I have to go to the dealers to have the suspension geometry checked or is it best too?

[Raffe]

You need somewhere that can do a decent 4 wheel laser alignment, dealership is as good a place as any to start.

For reference I paid £70 from a specialist with a Hunter 4 wheel laser alignment machine.

[dave7268]

Cheers Raffe

Sorry for sounding stupid (cos I am  ) but I take it that the suspension geometry check is a 4 wheel laser alignment?

Also is the Hunter 4 machine the best one?

[Booth11]

Info on here might be of help http://www.alignmycar.co.uk  If you look under centre locator and put in your town it will find the nearest Hunter equipped place

There are different geometry check systems around but Hunter 4 wheel is among the best.  I had mine done on this system which uses lasers/optical cameras.  It cost me £85 and was well worth it and i will be doing it every year now.

[dave7268]

Nice one Booth.   

That link has helped me locate several places close to where I live.

Much appreciated for all your help guys.

[Jimble]

Thanks for that Booth, turns out my very local tyre fitter has the Hunter Hawkeye 4 wheel allignment equipment AND the Artiglio touchless tyre fitting machine! Fingers crossed i never need the latter but it's great knowing it's there!