BMW 4 Series stuttering issue

chez1hunts

Hoping some one may be able to give me some advice on an issue thats just started on my 63 plate 4 series 420d X-Drive 55K miles, serviced at BMW in December.

All of a sudden when acceleration my car will slightly stutter, you can feel it each time, it's an automatic. It's not all the time this is the frustrating thing. I took it to a local so called BMW specialist who I'm told put it on the diagnostics machine and found no issues. They actually pointed to the front tyre I'd had put on new that week. About the same time I first noticed the issue .Saying it was the incorrect sort. I went back to the tyre company who after a long conversation agreed to replaced the tyre with another BMW tyre , also asked them to replaced the other front one that had 2 small bulges from bloody pot holes.

Thought hopefully this would sort the issue but sadly just as bad. Looks like I may have to take it to the local BMW garage. Not going to be cheap.

maxwell

Have a read here F20 xDrive Stutter on accelaration - solved -

chez1hunts

Jesus 2.5k . OMG I hope that’s not the issue. Best get it booked in for this week.

chez1hunts

Reading more and more information on the net I'm starting to think the unbalancing and tyre make is causing the issue .Causing issues with the transfer box, looks like it's very common. BMW advice same make of tyres and I'm reading that tread should stay within 2mm.

I've just added 2 new front tyres that are different make to rears, I hadn't noticed the issue before the new tyres went on, firstly I'm going to add 2 new rears same make as front.

Bl4ckGryph0n

Just don’t change single tyres. Just don’t do it. It changes a lot of things and can cause for some seriously unbalanced handling. Also run them at the correct pressure, BMW can be very sensitive to that.

I must admit that I just don’t get it when people have a nice car like that but then have all sorts of different tyres on it. You would put on two totally different shoes yourself would you? That is what you are doing to the car.

Saying all that; stuttering is a new one to me as a notable effect of having different tyres. Perhaps it is the description or word being used as with stuttering I’d gravitate towards engine problems.

un1eash

Its the xdrive 4wd system that doesn't like mismatched tyres of type and age. Audi 4wd can be the same. The car detects a difference in grip levels and trys to adjust power distribution.

Bl4ckGryph0n

Are all 420d xdrives then? I’m sorry if I missed that from the original post.

And yes definitely don’t do that on a four wheel drive system. And even when you do, just go to a multi story car park with a wet floor and on full lock

MarkNorton1

The only thing that springs to mind in your situation is maybe the start of an EGR valve issue, tends to start off with the odd stutter etc then gets worse with the car eventually reporting an error, usually will say drivetrain issue, has been a fairly common issue on BMW’s and Minis for a little while now but might be worth mentioning when booking in.

un1eash

No not all, its an assumption being made.

chez1hunts

It was a case of not having a choice at the time, we hit a pot hole that caused a rip in the front tyre , we managed to get to a local tyre supplier who had one in stock that fitted my car.

Would of happily paid to have both the front 2 changed at the same time if it had been possible as the other had a slight bulge also, the one tyre got changed and that's when I noticed the issue. The first new tyre wasn't even a recommended STAR tyre. Then they changed the front 2 to star tyres recommended by BMW. Issue was still there .

Now have 4 new continental tyres all the same make and issue has gone, haven't given it a good run but seems to of been sorted now with the back 2 also being changed. So 900£ lighter with 4 brand new tyres.

Hopefully I've seen the back of the issue now. Lesson learnt on mixing tryes also. Costly one at that.