george44

Guys,
I've tried doing a search on this topic, but none of the posts seem relevent to my particular problem, and as I'm on dial-up sat in my hotel room, thought it easier to create a new post.

My 05 530d Sport E60 had it's first service last week (14k miles,Scope1 and just oil change and filter)

I can't imagine they messed with anything else, but I've now noticed a 'flat spot' just as I tickle the throttle. It isn't rpm dependant as I can reproduce it in any gear, but just as I press the throttle from completely off, the revs start to rise, then drop slightly, before picking up again.
A few times I've managed to hold it in the 'dead spot' and it feels as rought as hell. The rest of the throttle movement is fine, nice and smooth acceleration.

I'm assuming the throttle is some 'fly-by-wire'? Not sure if it's a potentiometer, of some kind of optical encoder. Not that it matters, as it's not going to be me trying to fix it....

Just wondering if anyone else has had a similar problem, and what the fix was?

Cheers.

needforspeed

Does it affect acceleration? - I generally find that when accelerating that there are points at which the revs stay steady, but I continue to accelerate - I believe that this is the torque converter (assume you have auto) spooling up - revs then increase when it is 'locked'.

Having said that - the way you descibe it - it sounds like something more worrying.

george44

I can accelerate out of it, and to be honest, it's not really noticeable when accelerating. It seems to be the very first few degrees of movement of the throttle, what ever gear I'm in (yes stepbox).

I can understand why you mention the torque converter, but this is something different.
If I just press the throttle (whatever speed I'm doing or gear I'm in), and hold it there, it's almost like the brakes coming on the car, and quite jerky. (Feels a bit like when a coil used to start breaking down under load on a petrol car).

I don't know how exactly the throttle is hooked up, but it certainly feels like a dirty electrical signal coming from the pedal itself. I'm pretty sure it's directly related to the pedal position.
The annoying thing is, in 6th gear doing about 80mph, I find I don't need much throttle pedal movement to sustain this sort of speed. And that's exactly where this problem shows the most.

Anyway, I'm hoping to get it booked into Rydale next week sometime, so will let you the post portem.

Thanks for you reply.

lawman

Totaly smooth on mine, so I think you have a problem.

0700700

what does a torque converter have to do with anything else than hard starts

needforspeed

Well the torque converter is going to come into play whenever you change gear isn't it - since this does the job of a clutch in the auto gearbox.

Other forum members have suggested that the torque converter lockup is the reason for the behaviour I described which is clearer different from the original posters problem.

http://en.wikipedia.org/wiki/Torque_converter

The above describes the way the converter works - I'm still not sure if this is the reason for the revs remaining static when I floor my car sometimes - or if this is the turbo coming in a full boost.