XSeries-forum

Hi guys , looking for some help I’ve read into plenty of forums on line in regards to my problem but hoping use can shed abit more light.
Recently purchased 2005 X3 xdrive car was running fine up until about week ago suddenly started hearing a kind of clunking noise that sounds like coming from rear and also a slight judder on acceleration this only seems to happen at low speeds and after the car has been driven for about 10/15 mins. No noise or hesitation for first 10mins or so. I’ve had garage look at it and can’t seem to find the exact problem!!! After some research I’ve come to Learn not having correct tyres can also cause these symptoms I have not changed any tyres since purchasing and been driving the car around a month before the noise began. I currently have 235/50/18 on front and 255/45/18 rear all same brand although rears do need replacing as much more worn than front?. Can anybody advise on this before I go replacing all tyres.?? Spoken to numerous garages and tyre companies who seem to think tyres cannot cause issues I’ve stated above... Thanks guys !!

Yes tyres can cause big problems and could well be your problem.
With the staggered setup is more prone to the problem and can end up costing thousands to put right.
It's costly but a new set of star marked could fix your problem if you have a big difference it tread front to rear.
Do a search for "differential wind up" or diff windup.

Shows just how unaware of the situation many tyre shops are, but many do know. I have a colleague at work who used to work in the industry and knew all about it. The compounds are the same but the construction and sizes are slightly different - and stay within the 1.5% tolerance needed.

It’s as above and also applies to Mercedes, Audi and a few more - who also have the specifically marked tyres - where an all wheel drive and staggered wheel/tyres are used. It’s all about the diameter of each and also whether they expand at speed. Unless both a matched and controlled within very tight limits the problems above can occur.

One worn pair and one not so worn pair has the same effect. If you need to change one pair, unless the other is nearly new you will probably be better to change all 4 as a set.

Thanks for ur Input guys if I went to a squared set up, 235/50/18 u reckon that would cause me less issues? I can get hold of 4 matching of that size today and all tyres with 5ml thread, although they are not star rated!? I understand until I make the change I will never know. But all advice is welcome.

Obviously if this corrects my problem or even reduces it I would then feel more comfortable about spending the money on 4 star rated tyres. Just don’t want to be spending 5-600£ on tyres and still have same issues so trying to go about it the cheaper way at first as money is pretty tight right now !

You need rims that are all the same size, or is that what you were looking at?

Yes rims are all same size mate

Update incase it helps anybody else. Changed tyres this morning and it’s literally like driving a different car. No noise no engine hesitation. Crazy to think tyres can have that effect!! Even worse that Bmw and numerous tyre shops advised tyres would not be the cause. Thanks again!