Grinding Noise

[maltaconvoys]

First an introduction - I’ve owned a pre-facelift MG5 LR Excite for about three weeks and have driven it about 650 miles so far. Until today, I’ve had no concerns, and have been enjoying driving it.

This afternoon I drove to town, a short six mile journey, and parked in a multi-storey. As I did I noticed a slight grinding noise when the steering was at full lock. I put it down to hearing the power steering motor more due to the lack of engine noise. On the drive home (Eco Mode, Kers 3) I noticed a slight clunk from under the car, then a little further on as I pulled away from some lights a terrible metallic grinding noise to the front of the car. I put on the emergency flashers, stopped, put the car in neutral and turned off the auto handbrake, then I put the car in normal mode and drove on, another clunk and the grinding stopped. Then more grinding as I steered the car around a roundabout, but nothing else for the remainder of the journey.

Any thoughts as to the cause? I wondered whether the auto handbrake was sticking. Could it just have been a stone in the wheel?

 

[5teep]

It's fairly common I think. Happens on my 5SR also and I've never worked out what causes it. My car has been serviced twice and they've never highlighted anything.

 

[Jomarkh]

Mine does something similar, I notice it mainly on roundabouts.

 

[Lovemyev]

Long shot !.
Take a look at this thread ?.
Could it be similar to your problem ?.

Turning right squealing

Anybody experienced a fairly loud squealing type noise when turning ? I noticed it going around roundabout and when slow turning, but a colleague mentioned it this morning, that when I left the office car park yesterday, the noise was quite loud.

www.mgevs.com

 

[maltaconvoys]

Long shot !.
Take a look at this thread ?.
Could it be similar to your problem ?.

Turning right squealing

Anybody experienced a fairly loud squealing type noise when turning ? I noticed it going around roundabout and when slow turning, but a colleague mentioned it this morning, that when I left the office car park yesterday, the noise was quite loud.

www.mgevs.com

It might be. The sound wasn’t as squealing as that - more of a metallic grinding. I gave the wheel arches and brakes area a hose down earlier in case it dislodged a stuck stone. The rural roads have been quite bad with the rain and it would be easy to pick up a stone when going through deep puddles. I will see if the sound recurs tomorrow.

 

[maltaconvoys]

It's fairly common I think. Happens on my 5SR also and I've never worked out what causes it. My car has been serviced twice and they've never highlighted anything.

It’s good to know I’m not alone. It’s not a sound that inspires mechanical confidence in the vehicle!

 

[5teep]

It’s good to know I’m not alone. It’s not a sound that inspires mechanical confidence in the vehicle!

True but I've done 50k in mine now and it hasn't failed yet

Except for the rear tracking/suspension making the rear tyres wear on the inside edge only..

 

[Lovemyev]

True but I've done 50k in mine now and it hasn't failed yet

Except for the rear tracking/suspension making the rear tyres wear on the inside edge only..

Rotate your wheels / tyres in a front to back config could be a answer ?.
VAG recommend wheel / tyre rotation every 5,000 miles !.

 

[5teep]

Rotate your wheels / tyres in a front to back config could be a answer ?.
VAG recommend wheel / tyre rotation every 5,000 miles !.

I had a puncture a few weeks ago and got both rear tyres replaced when we found the wear. I put it in to the dealer to get it checked, told them it was wearing the tyres on the inside edge.

Report came back "unable to find any wear on the inside edge"

 

[Lovemyev]

The rear tyres on FWD cars on the VAG models have a similar wear condition, where by the rear tyres ( if left on the same location at the rear ) produce a strange wear pattern that is some times named as "Shark Toothing".
All the steering geometry checks out 100% to the factory spec's so tyre rotation has advised every 5,000 miles as a remedy.

 

[Gomev]

The rear tyres on FWD cars on the VAG models have a similar wear condition, where by the rear tyres ( if left on the same location at the rear ) produce a strange wear pattern that is some times named as "Shark Toothing".
All the steering geometry checks out 100% to the factory spec's so tyre rotation has advised every 5,000 miles as a remedy.

It's not really a remedy though is it ? It's just sharing the problem with more tyres.

 

[maltaconvoys]

It might be. The sound wasn’t as squealing as that - more of a metallic grinding. I gave the wheel arches and brakes area a hose down earlier in case it dislodged a stuck stone. The rural roads have been quite bad with the rain and it would be easy to pick up a stone when going through deep puddles. I will see if the sound recurs tomorrow.

The noise hasn’t come back this morning. I attempted to replicate the driving actions before it occurred and drove it in various combinations of mode and Kers to see if it happened again. I’m guessing it was grit in the brake which has since dislodged.

 

[Mr Gear]

Mine did a very similar thing last month, sounded awful, grinding, then the noise just went after a couple of miles, I was in normal mode with kers 2

 

[am84]

Mine makes a noise when the auto break releases.

 

[Rookery]

I had a loud metallic screeching noise from the front of my MG5 and as someone has already mentioned I had picked up a stone and it was stuck between the brake disc and the rear casing. I was so worried as I had just completed a 200 mile journey and it started 100 yds from my home so I called the AA out and he new straight away after hearing it. He said it a very common thing to happen although I have been driving for 50 years I have never experienced this before, however most of my early cars only had brake drums.

 

[Lovemyev]

It's not really a remedy though is it ? It's just sharing the problem with more tyres.

It's accepted by VW dealers that the way the rear suspension has been designed and set up on some FWD models just produces this condition at the rear.
There is NO remedy / fix unfortunately, this is why they recommend a wheel & tyre rotation every 5,000 miles, it is recommended in the owners hand book as well.
This strange "stepped" tyre wear condition, is a very slow and gradual process and is hard to detect in the early life of the tyres.
Strangely, the condition appears to accelerate quickly IF the tyre is left in the same location for the entire life of the tyre.
This then results in the tyres on the rear, get replaced prematurely due to this condition.
Rotating them every 5,000 mies does not solve the problem, but it does extend the life of the tyres.
I have owned three VW Polo's and five VW Golf's over the years and this condition has existed on every single car.

 

[Gomev]

It's accepted by VW dealers that the way the rear suspension has been designed and set up on some FWD models just produces this condition at the rear.
There is NO remedy / fix unfortunately, this is why they recommend a wheel & tyre rotation every 5,000 miles, it is recommended in the owners hand book as well.
This strange "stepped" tyre wear condition, is a very slow and gradual process and is hard to detect in the early life of the tyres.
Strangely, the condition appears to accelerate quickly IF the tyre is left in the same location for the entire life of the tyre.
This then results in the tyres on the rear, get replaced prematurely due to this condition.
Rotating them every 5,000 mies does not solve the problem, but it does extend the life of the tyres.
I have owned three VW Polo's and five VW Golf's over the years and this condition has existed on every single car.

Just poor design then. Rotation may prolong the life of the initial rears but also shortens the life of the initial fronts.

 

[Lovemyev]

Just poor design then. Rotation may prolong the life of the initial rears but also shortens the life of the initial fronts.

I guess so, it has been this way since the first model Polo’s and it is a condition on all Golf’s I have ever seen.
Therefore, it has to be common issue on the Audi A3 models etc.
Come to think of it, this tyre wear “stepping”was also a thing on the classic Mini’s.
Don’t get me wrong here, it’s really not very bad, but it is there aright.
You can spot even a relative newish car that has not had a tyre rotation, very easily.
E.G. - VW in for its first service, car has covered say 8,000 miles.
Go to one of the rear tyres, place the palm of your hand flat on the top of the tyre tread, towards the front of the car, then drag the flat palm of your hand, back towards the rear of the car.
That is when you are likely to feel the shark tooth effect ( some refer to it as sword tooth effect as well ) biting into the skin of the palm of your hand.
If the tyre has been in that same location for about 12,000 miles, you can actually see the affect on the tread, if you know what to look for.
Now repeat this process on the front tyre, completely smooth front to back.
Some customers who’s tyres have not been rotated, even report a “Droning” noise coming from the rear of the car at about 50 - 60 Mph.
Absolutely convinced they have bad rear wheel bearings, when in fact it is very likely to be this shark tooth wear causing the condition.
Rotation at 5,000 miles helps avoids this type of condition from manifesting itself.
It’s one of them anomalies of the design ?.
All cars have their own different strange quicks and features.
While on the subject of tyres.
RWD - BWW’s have a well known feature of wearing out the centre section of the tyres WAY before the outer edges.
Tyres being replaced prematurely once again.
Owned being blamed for making spirted starts from the traffic lights.
Nope - Mainly down to manufactures tyre pressures being 2 Psi to high.
Reduce the pressure by 2 Psi and they will wear correctly across the whole thread width.
Ask me how I know .

 

[Gomev]

I guess so, it has been this way since the first model Polo’s and it is a condition on all Golf’s I have ever seen.
Therefore, it has to be common issue on the Audi A3 models etc.
Come to think of it, this tyre wear “stepping”was also a thing on the classic Mini’s.
Don’t get me wrong here, it’s really not very bad, but it is there aright.
You can spot even a relative newish car that has not had a tyre rotation, very easily.
E.G. - VW in for its first service, car has covered say 8,000 miles.
Go to one of the rear tyres, place the palm of your hand flat on the top of the tyre tread, towards the front of the car, then drag the flat palm of your hand, back towards the rear of the car.
That is when you are likely to feel the shark tooth effect ( some refer to it as sword tooth effect as well ) biting into the skin of the palm of your hand.
If the tyre has been in that same location for about 12,000 miles, you can actually see the affect on the tread, if you know what to look for.
Now repeat this process on the front tyre, completely smooth front to back.
Some customers who’s tyres have not been rotated, even report a “Droning” noise coming from the rear of the car at about 50 - 60 Mph.
Absolutely convinced they have bad rear wheel bearings, when in fact it is very likely to be this shark tooth wear causing the condition.
Rotation at 5,000 miles helps avoids this type of condition from manifesting itself.
It’s one of them anomalies of the design ?.
All cars have their own different strange quicks and features.
While on the subject of tyres.
RWD - BWW’s have a well known feature of wearing out the centre section of the tyres WAY before the outer edges.
Tyres being replaced prematurely once again.
Owned being blamed for making spirted starts from the traffic lights.
Nope - Mainly down to manufactures tyre pressures being 2 Psi to high.
Reduce the pressure by 2 Psi and they will wear correctly across the whole thread width.
Ask me how I know .

That is really awful design, whereby for an average mileage per year driver you are recommended by the manufacturer to rotate the wheels twice a year. Dreadful, really dreadful.

 

[Lovemyev]

Just poor design then. .

If you Google this condition, it pops up straight away.
There is loads of info on this condition which is wide spread on a number of cars with trailing wheels ( FWD ).
Here is just a quick snippet of why this happens, note the date on this service bulletin!. 2008 !.

Technical product information Transaction No.: 2019800/1

Saw Tooth Tyre Wear Release date: 23-Dec-2008

Customer statement / workshop findings
Saw tooth tyre wear / tyre noise.

Technical background
A Major cause of annoying tyre / road noise is "Heal and Toe wear". This is the outwardly visible (and audible) manifestation of various distortional forces at work on the tread. To explain this, it is better to first say something about "tread design".
Tread grooves and sipes - a source of noise - are absolutely essential in ensuring safety on wet and flooded roads. In the case of low profile tyres in particular, a higher percentage of tread void is necessary to take up and channel the water, while a hydrodynamic tread pattern design is needed to ensure water displacement.
The upshot of this is "detached blocks" in the shoulders. Because of how the tyre rolls over the road, the blocks can suffer heel and toe wear under certain operating conditions.
When a tyre rolls, the individual blocks in the tread are deformed.
On entry into the contact patch, the blocks are compressed. In exiting the contact patch, the blocks rub against the road surface and spring back to their original shape, resulting in higher abrasion where the lug tapers off.
This wear pattern is more likely to occur on non powered wheel positions.
If the tyre is driven in compliance with the specific operating conditions, the difference in height between the front and rear edges of the block does not exceed 0.8mm, a level at which no noticeable deterioration in the tyre's characteristics is to be expected. More conspicuous heel and toe wear points to specific operating conditions (improper inflation pressures, excessive toe in, driving style).
To arrive at an improvement in the tyre wear pattern and a relative reduction in road noise it is imperative that tyre pressures are maintained regularly in accordance with the manufacturers specification. Also rotating the wheels has the effect of evenly distributing wear, so that the tyre returns to its original favourable noise level after a certain distance.
Above all please remember that tyre wear is unavoidable as a frictional force must be present between the tyre and road surface.

Below is a photo that displays the condition of sword tooth and the condition that BMW’s suffer from, where the centre section gets worn away prematurely.