Last Wednesday morning whilst on the NCP known as the M25, I heard a knocking that appears around 50mph and which becomes more noticeable at around 60mph. I can also feel the knocking lightly through the accelerator pedal and steering wheel.

Sticking the car in neutral to coast makes no difference and the knocking speed increases with the road speed, but not the volume. Car is a 2011 CR170 with just over 32k from new. Bloody annoying, especially if this ends up being expensive, albeit I'll go after goodwill from SUK, but pretty poor for a low mileage car. Of course, I appreciate it could be a myriad of causes, but ideas peeps?

Edited 7 June, 201610 yr by numskull

Track rod end? Just a guess.

Dave

Balance weight fallen off a wheel maybe?

Track rod end? Just a guess.

Dave

Hmmm, never thought of that - cheers Dave

 

Balance weight fallen off a wheel maybe?

 

Nice one.

 

I guess a decent Tyre replacemt co can check both of these.

 

Thanks again guys!

Edited 8 June, 201610 yr by numskull

Check link arms at front aswell

Loose under tray flapping?

look through the wheels at the calipers, and make sure you can see a large spring, I had the same thing, the NS caliper spring had gone missing a 1 min job to replace

Cheers everyone - I'll check the suggestions and report back!

I found the culprit. I removed the OS front wheel and found this lot on the inside tyrewall...

 

The car is fitted with Vredestein Ultratrac Cento on all four corners.

 

 

The bulge expands with centrifugal force thereby hitting the road surface and causing the knocking. Unbelievable!

 

There are six cracks in total on the inside tyre wall. Now I don't know if these have been caused due to a run flat by the previous owner, because I have not had a problem with the tyres since purchasing the car, or if this is a manufacturing fault, but both fronts are getting changed tomorrow.

 

I've decided to try a pair of Infinity Ecomax, following on from a mate who's fitted two sets of these in 18 months on his 2011 A6 with the first covering 24k miles and has nothing but good words to say about them, wet or dry. For £90 fitted for the pair given the tiny mileages I do, I thought it was worth a punt. They also get pretty good ratings on Tyre Reviews.

 

I'll report back with my findings, but I'm so pleased it wasn't an expensive mechanical item.

Edited 10 June, 201610 yr by numskull

Look at the state of these rear tyres, they were making a right old racket. The rest of the tyres were legal , just this inside edge wear . something to look out for as hard to spot on rears

Edited 11 June, 201610 yr by terrytowelling

Look at the state of these rear tyres, they were making a right old racket. The rest of the tyres were legal , just this inside edge wear . something to look out for as hard to spot on rears

Wow. They're a real mess!

I didn't get ours changed on Sat, due to the inept idiot at Halfords "Autocare" (sic) in Kingston, Surrey. Got there at 08.20 for an 08.30 appointment. When I finally got the the twerp behind the reception desk (the one that had told another customer driving a Golf how a failed oxygen sensor can cause his cat to breakup and fall apart, but in any event there'd be a £49.99 diagnostic charge) then said they'd be a THREE hour wait, cost there were three customers ahead of me! Oddly, I told them to shove it. Not once did he apologise to me, nor to any of the other people he'd let down that morning. When I left at 08.45, they'd still not started on a single car. I told the aforementioned Golf driver not to get his car looked at by them, as they're clearly going to rip him off, but to go to an indie VAG specialist. As for me, Asda Tyres were great when I moaned and today they've given me a discount as an apology, so really good customer service from them; I'm rebooked for tomorrow at a local "proper" indie tyre dealer.

Had the tyres changed at K&P Tyres in Ewell yesterday. Great service. Also found the NS front had a large bulge an very large 25mm crack on the inside wall. I've kept them and have started a warranty claim with Vresdestein.

How many of those split speed bumps are near you, a taxi owner had his car fail due to the inside walls showing splits, even though the tyre treads where compleatly leagal to look at

How many of those split speed bumps are near you, a taxi owner had his car fail due to the inside walls showing splits, even though the tyre treads where compleatly leagal to look at

Quite a few, Skip, but to be honest, I've never had any problems with these before. The sidewalls are so stiff on low profiles your have to be hitting them at high speeds again and again to cause a failure. Also, as I think I mentioned, there is zero sign of damage internally, which there would be with kirb damage, and low pressure would show externally. But I've never seen random cracking like this. It's most odd....

I have the same from Dunlop winter tyres just removed from my Merc  with still about 6mm on them inside wall all cracked at varoius places around tyre 
Bloody expensive tyres but brilliant on the slidey stuff

Awaiting uplift from my tyreman.

Will let you know how I get on