Juddering

Hi guys,

Just picked up Z4M Coupe, 07 reg, 12,000 miles on clock.

AA inspection guy drove it and reported some juddering and thought it was a clutch problem.

I drove it and experienced a little of it but put it down to driving style and getting used to the car rather than a mechanical problem.

I just had a colleague drive it who has an M3 and although he generally caned it around, thought it drove great and the clutch was better than his.

Does anyone understand what I mean or experienced the same thing? I think (hope) its just getting used to driving the car. (Coming from a Mini Cooper S)

I will prob take to BMW for piece of mind.
 
Firstly what was the point of having an AA inspection and then ignore the guys comments/advice? If it is the clutch then it's your problem now....! Secondly I hope it's not a serious problem - not sure about the M series but the earlier Zeds (and probably the current) were fitted with a CDV - Clutch Delay Valve - in essence a restrictor between the pedal and clutch which reduced the flow of clutch fluid as the clutch was released supposedly to ease reduce clutch judder and make for a smooth getaway. It does just the opposite and can create judder when moving off in 1st and changing to 2nd. This can be replaced - do a search there are many threads on the subject.
 
My last BMW judder was a partially seized front brake caliper. Almost felt like a wheel balancing weight had fallen off and occasionally disappeared completely. Easy to tell if that's the issue or not as one front wheel will be much hotter than the other when you get out!

PS Well done on getting your car; you're one step ahead of me! where did you get your car from -was it either of the Hampshire Classics or ex Sytner Canary Wharf ones that have been advertised on PistonHeads?
 
It was the ex Sytner Canary Wharf one. Well spotted!

Presumably the CDV is not something BMW will remove?

In answer to why ignore his advice, all things considered, it seemed a good deal and the cost to replace a clutch if necessary, would still mean it was a good deal in my eyes. And it doesnt happen very often. Ill get it checked out at BMW and see what they say.
 
Having read about CDV, I think it must be that.

When I said juddering, I mean more like kangarooing, like when your a learner, but at speed and not stalling. Does that make sense?

Anyone know someone in London who will do it for me?
 
playalistic said:
Bad fuel perhaps?
I'd agree with Alan, however the point about fuel is worth looking at. I have noticed my //M is significantly smoother (and less prone to judder) with Tesco99 in the tank.
 
thattallchap said:
playalistic said:
Bad fuel perhaps?
I'd agree with Alan, however the point about fuel is worth looking at. I have noticed my //M is significantly smoother (and less prone to judder) with Tesco99 in the tank.

I agree with that, I've been using Tesco99 for the last year and have found the kangarooing to be negligible. The last couple of tanks have been Vpower and the issue is much more prominent.
 
My zed will shudder when in 1st and 2nd when its cold. The engine surges.

Otherwise if I'm particularly uncoordinated at changing and have the CDV in, it can judder a bit.
 
Another vote for Tesco 99 - it's helped ease the juddering without me having to remove the CDV.

Gareth :)
 
Mine judders a little when changing between ->1 and 1->2 gears. Its the CDV im pretty certain... Mine is more noticable at lower RPM. As the engine is so tractable you barely need throttle when pulling away, although this does sometimes cause the engine to hesitate. The CDV accenuates this...
 
Ive since ordered a modified CDV from Zeckhausen and awaiting its arrival. Anyone know somewhere in London to get it fitted? Preferable north or east.
 
The modified CDV is worth doing as it allows the clutch to engage at your pace and not at the artificial one imposed by BMW. What I would say is don't expect it to eradicate the kangarooing issue, it gives you a bit more control over the clutch and allows you to react better in bringing the juddering under control. Beyond that I think you just get used to driving around the characteristic as with familiarity you can anticipate when it's going to happen and take the appropriate action ie floor the accelerator pedal or lift off it. I still think the brand of petrol has a large bearing though.
 
dgm said:
..Beyond that I think you just get used to driving around the characteristic as with familiarity you can anticipate when it's going to happen and take the appropriate action ie floor the accelerator pedal or lift off it. I still think the brand of petrol has a large bearing though.
Agreed.. I was already used to it when I had the CDV removed, so it didn't make any difference. I think you're better off getting used to the car over time and using proper petrol, allowing the ECU to adjust after a few tanks of the thick stuff as it won't react immediately.

Incidentally, it's only *my* opinion, but having seen the process of knocking out the middle of the existing CDV with a punch, (20 seconds tops) I certainly wouldn't spend any money on a replacement fixing.
 
yes, although there is suggestion that the pipe is then stretched slightly, so I'd still go for removing the centre.
 
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