[jimscamp]

So, since I’ve had this car I’ve felt a “slight” undulation in the front passenger front corner.

BMW looked at everything and said it was all fine.

I then got new Michelin PS4S tyres in May from a reputable tyre dealer and they performed a fresh alignement, looked at the suspension and gave everything a thumbs up, and after that the undulation vanished and I’ve not detected it since.

The tyres have done 4000 easy miles, it’s a family car with young kids in the back, and I’m the only driver.

Today, I just had a little look at the tyres as the weathers getting cold and was shocked to see the thread starting to show on the edge!!

Checked then right hand front tyre and I can see a similar subtle wear pattern but no thread yet.

The rears look fine to me, including a photo in case you guys see anything concerning (it’s the photo that doesn’t have the weird wear).

Now my questions are…

1) What the heck could be causing this, BMW and third party okayed the suspension, it’s a 3 year old car and it had the tyres aligned recently.

2) The car has a month left on its BMW certified pre-owned warranty, if it is the suspension, should this be covered? Especially as I’ve raised this undulating sensation within a week of receiving the car (although nearly 11 months have passed since they said it was fine).

3) if the rear tyres are fine and have decent tread left, would they still need changing due to x-drive, or would it just be the two front tyres that need to be swapped?

Thanks for your thoughts!

[Numark318i]

Have you had the alignment checked? **edit

I see you had them aligned recently. Wondering what others say.

[Neusser]

Originally Posted by Numark318i

Have you had the alignment checked? **edit

I see you had them aligned recently. Wondering what others say.

This. Get another alignment. Seems like some kind of camber issue.

AWD cars can be more difficult to align than RWD.

[tsbrown]

What are your tire pressures f/r? I’ve run 36/41 psi for 4 years on Michelin PS AS3+ (similar to PS4S) with zero issues. Only recently dropped that to 32/36 for a more compliant ride. But your issue sounds more like alignment as others have suggested.

Btw, looks like you have a Mediterranean Blue car like mine. Lovely color.

[jimscamp]

Originally Posted by tsbrown

What are your tire pressures f/r? I’ve run 36/41 psi for 4 years on Michelin PS AS3+ (similar to PS4S) with zero issues. Only recently dropped that to 32/36 for a more compliant ride. But your issue sounds more like alignment as others have suggested.

Btw, looks like you have a Mediterranean Blue car like mine. Lovely color.

Hi there, it's been ran between 36-38 bar depending on the weather and load.

The cars in with a main dealer right now, so I'll update one I get to the bottom of it.

Really hoping it's not a suspension issue - but there's a chance it might be that the pressure was too low and it's been riding the outer edges.

I always had it in line with the BMW infotainment recommended pressures, but maybe they're quoting runflat pressure?

[tsbrown]

36-38psi should be fine with the PS4S on the G30. That’s similar to what I ran on my F30 340i with those tires and slightly lighter car. The higher pressures listed on the door jam and owner manual seem to be to promote higher fuel efficiency. Excessive wear on edges seems to point more to alignment, camber.

[tsbrown]

One other comment, the PS4S is a summer max performance tire and is not meant to be used in temperatures below 40F/7C, x drive or not. They will get hard as a hockey puck in cold weather and you’ll have no traction. Appears you’re in the UK so not sure what winter weather you get but I would recommend winter tires until it gets warm enough for the PS4S tires. My AS3+ tires are evenly worn down to 4-5mm, still very usable in warm/dry conditions but marginal for even mild winters so I’m considering replacing them.

[jimscamp]

Thanks for the advice!

Winter's only just gone down to 5C this past week and I've not done much driving whilst it's been this cold, so I'd be surprised if that was the cause, but noted

[Warp Ten]

You said the car is in with a "main dealer" but I am not sure what that means--a BMW dealer? Did you ever go back to the tire dealer who initially installed the Michelins for you? Maybe there was a production problem with a batch of tires. They would be able to find that out or give you some ideas about what has been causing this. Also, since they did an alignment on tire installation not too long ago, they should certainly be responsible for that I would think. Good luck on figuring it out.--Bob

[jimscamp]

Yea, currently with local BMW dealer due to fearing suspension issues and the car still having warranty.

The tyre place has actually ceased operations now, which is strange - it opened in our area earlier in the year, really professional set up and service, lots of great reviews on google and they even did a free check a few weeks after alignment to make sure nothing had slipped…

Went to them first to try and sort this and they’re now closed down!

I have a feeling they put the wrong values in their alignment computer system as it took them a while to realise the car was a G series, rather than F and were struggling to find it in their setup files.

I’ve not hit any notable pot holes, so I can’t believe alignment had shifted that much in both front wheels across a few months, and the dealer is saying my suspension all looks to be in great shape, so it’s not a component issue (I hope ).

[jimscamp]

So, here’s an update…

Got about 500 miles on the new front tyres now and noticed the little Michelin man on the outer edge is starting to show wear already.

Is this a normal spot to show wear on the front tyres?

For all I know it’s exactly where the contact patch needs to be, but it’s worrying me that it’s in a similar place that showed crazy wear in the ruined tyres!!

Any thoughts, or if PS4S owners could have a little look at their wear and see how the little Michelin man is holding up would be greatly appreciated!

[Chappers 71]

I’ve now put a few hundred miles on the 4 ZPs & they’re showing no sign of any wear on the edges even with my enthusiastic cornering. Maybes get the alignment checked again, most big tyre places do a free check.

[Neusser]

Originally Posted by jimscamp

So, here’s an update…

Got about 500 miles on the new front tyres now and noticed the little Michelin man on the outer edge is starting to show wear already.

Is this a normal spot to show wear on the front tyres?

For all I know it’s exactly where the contact patch needs to be, but it’s worrying me that it’s in a similar place that showed crazy wear in the ruined tyres!!

Any thoughts, or if PS4S owners could have a little look at their wear and see how the little Michelin man is holding up would be greatly appreciated!

While the little MM is not officially an indicator for proper edge wear, a lot of track guys use it for just that.

The wear should go slightly into the MM, and would indicate that you are using all of the tread face. Yours looks slightly deeper. Perhaps try multiple tire gauges to check for proper pressure. Barring that, you have an alignment/component-related issue.

[remmib]

Originally Posted by jimscamp

So, here’s an update…

Got about 500 miles on the new front tyres now and noticed the little Michelin man on the outer edge is starting to show wear already.

Is this a normal spot to show wear on the front tyres?

For all I know it’s exactly where the contact patch needs to be, but it’s worrying me that it’s in a similar place that showed crazy wear in the ruined tyres!!

Any thoughts, or if PS4S owners could have a little look at their wear and see how the little Michelin man is holding up would be greatly appreciated!

It does look like you have excessive wear on the outer edge. Looked at my PS4S from 2018 with no outer edge wear, and slight inner edge wear. My car it lowered, so it’s has more camber in the front.

[jimscamp]

Thanks guys!

During the troubleshooting of this, the dealership did a full check of the suspension and a fresh alignment of all 4 wheels about 3 weeks ago.

These tyres have now done 400 miles and it looks like something weird is still going on?!

The car is 3 years old, driven around town as a family hauler and not thrashed, there’s no weirdness in the steering or with the handling.

Anyone have any thoughts on what the issue could be if the dealership are saying the suspension and alignment are up to spec?

Could it be under-inflation?

They’re 2.5 bar on the front and 2.7 bar on the rear as per iDrive’s recommendation - but does iDrive assume they’re runflats which means I’m running them at wrong pressure?

[Neusser]

Originally Posted by jimscamp

Thanks guys!

During the troubleshooting of this, the dealership did a full check of the suspension and a fresh alignment of all 4 wheels about 3 weeks ago.

These tyres have now done 400 miles and it looks like something weird is still going on?!

The car is 3 years old, driven around town as a family hauler and not thrashed, there’s no weirdness in the steering or with the handling.

Anyone have any thoughts on what the issue could be if the dealership are saying the suspension and alignment are up to spec?

Could it be under-inflation?

They’re 2.5 bar on the front and 2.7 bar on the rear as per iDrive’s recommendation - but does iDrive assume they’re runflats which means I’m running them at wrong pressure?

Under inflation at 2.5 and 2.7? No.


On my 540 touring I run 2.1 bar front and rear in line with the Goodyear recommendation and I get perfect wear and much improved grip in the corners (on Goodyear F1s).

You have some kind of suspension hardwear or alignment issue.

[Chappers 71]

Hey Jim, did you get this sorted?

[430Scud]

Originally Posted by Neusser

This. Get another alignment. Seems like some kind of camber issue.

AWD cars can be more difficult to align than RWD.

Not necessarily, if the tires are toe'd inward, that can also cause outer edge tire wear.

[jimscamp]

Originally Posted by Chappers 71

Hey Jim, did you get this sorted?

Not yet, it's getting it's MOT next week so I'm going to corner the Service team and get to the bottom of it... the warranties up on the 25th, so need to have answers

One thing I've noticed is that the wear is uneven around the edge... these two photos are from the same tyre at different points, you'll see the wear is touching his hand on one and well into the body on the other.

[IMG][url=https://ibb.co/qDBrckM]

[IMG]

Also noticed chunks are starting to appear out of the tyre, anyone got any thoughts on if that's normal on PS4S?

[IMG][/IMG]

It's may be my gravel drive, but the car only runs on that for a matter of seconds and less than 10ft coming in and out the house... it's not like its a 2 mile dirt road...

It's annoying as the car is well looked after and isn't driven hard!

[Chappers 71]

The surface does look pretty chewed up considering you’ve only put 500 miles on them, lots of pick up from your gravel drive on the tyres, I suspect that may account for the tyres surface damage, PS4S are pretty soft possibly the transition from gravel to hard road is causing damage as the wheels turn & the picked up gravels pushed into the rubber before being flung off as wheels rotate.
Went out to my garage & had a look at my fronts which have now done similar miles to yours

Get some tarmac on that drive
You could lay two lines of large concrete or stone pavers the length of the drive & the width of the wheels apart so as you drive on & off the pavers rather than the stones

[jimscamp]

Just an update on this.

Car went into BMW for MOT and the SA got the technician to check the tyres and alignment.

Technician reported even wear on the new tyres, wasn’t concerned about the wear on the Michelin Man and it got green lights on their laser alignment machine as well as passing the MOT and their health check with full marks.

So apparently it’s all fine 🤷

Good news I suppose, although I’m still a little paranoid 🤣