Flat spot?

M

milu

Member
 doncaster
Thought it was my imagination last time i was out,but yesterday i was definitely feeling a flat spot at 4k revs.
Most noticeable in 4th,presumably because you dont zip by that point as quick as the lower gears.
Not doing it every time though.
Car now has 1800 miles on.
 
Is that 1800 miles since new? I assume it has a warranty then?

Try a different fuel to be sure first though (Tesco 99 RON or Optimax for example).
 
Yeah from new Tref.
Always run 99 or Optimax(habit from TVR days)....could be duff though.
I think fuel can go off too??
Perhaps i dont go through it fast enough...fill up every 3 weeks or so.
 
Drive it more! I don't use mine for commuting but I still fill up every week! :wink:

That colour combo sounds nice by the way. :thumbsup:
 
Could well be that it just needs a good cobweb blow out! You should know how to do this from your TVR days :-)
 
vanos related ? i often feel a hesitation midrevs but it comes back with so much more urgency it makes up for it.
 
I've noticed a couple of times, when quick shifting through town etc. on and off the gas, the vanos got a bit 'caught out', in 3rd or 4th, lower revs. As Andy says though, seems to come back strong !

Probably had it no more than 10 times in 44K miles since new....
 
If it's only got 1800 miles on it then it's not really run in yet and still very tight, it might be worth seeing if it improves with a few more miles on it.
 
Ha! I just posted at two BMW forums about my funny spot at 4K. Mine is most notable when just off the throttle -- say, gliding into a corner -- and the revs slowly decrease through 4000 RPM. The car lurches "on/off" and rocks me in my seat. Very annoying.

Well, went to my Ohio BMW dealer and the tech there had a 2008 M Coupe with 5000 miles on it. He rode mine, felt the problem, then he rode me in his and tried to replicate the problem. IT HAPPENED IN HIS, TOO! Crazy.

They wrote it up as a normal operating quirk -- speculating that the throttle flap was "hunting" or "flapping" due to being right on the edge of "on" and "off".

I also note a bit of hesitation in my motor between 3000 and 4000 rpm when I'm lightly acellerating.

Crazy. I would not expect this flaw. Maybe it is VANOS, maybe it is the throttle. He said the commands to the throttle from the pedal are very sensitive.

Jonny
 
I LOVE the colour of your car ! I was going to order Sepang but the dealer talked me out of it. It's my only regret with the MC.
 
Thanks.
I thought it would be a marmite colour but in fact ive had no negative comments from anyone who has seen it in the flesh,even from folk who aren't afraid of upsetting me!!
Loads of glitter in the sun too.

This months EVO has a Veyron in a similar colour.
 
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