Choppy throttle at low speeds (05 5pd Cooper)

[xtremepsionic]

I've searched but couldn't find anything that answers my question, so here goes...

During low speeds, for example, traffic jams, I find that the car will slightly jerk forwards and backwards when I'm in 1st/2nd gear, with no throttle input from me at all. It seems like the car's idle is not smooth, it doesn't know how to stay at a constant rpm, instead it gives the engine a little more gas, a little less... over and over. (car rolling at 1000rpm on flat road) Very annoying.

I've never owned a manual transmission car before, but I don't think this is very normal? The car idles fine obviously when you're out of gear, no strange noises or any RPM variations, its just in gear, let the car roll without any throttle (about 1000rpm), and it just jerks back and forth. Hell, you can even here a slight ticking noise from the drive train due to the car giving it more power, then less power.

[martyn413]

Hi there,

You need to work on your clutch control. When driving at low speeds you need to dip the clutch and apply a little gas.

My 05 Mini one is the same. Minis were not built to drive slowly as they hate low revs. On small cars you can move the car with just the clutch. this makes hill starts easy. out of the 7 cars i've driven, the mini is the best and the most fun factor.

[Eelke]

From your description it sounds like something other cars do to, depending on the circumstances. I have it in my classic Mini sometimes too. I'm not sure how it's caused, but it tends to happen when you are too "lumpy" with your paddle work (not smooth enough with throttle and clutch). And sometimes, you're just going to slow for the car to be able to move with the clutch fully engaged.

[fred3]

isn't depressed all the way then there's your problem. If you're feathering it(and that's not good for the clutch) then don't. If the clutch is depressed all the way then you have a problem. Get it to a dealer.

[Lawrothegreat]

If you are driving forwards at slow speeds, and not using the clutch whilst moving, the slowest you can go in 1st gear is about 4mph, and in 2nd gear 7mph, in a 05 5-speed cooper (assuming my speedometer is correct!)

[xtremepsionic]

Quote: Originally Posted by Eelke

it tends to happen when you are too "lumpy" with your paddle work (not smooth enough with throttle and clutch). And sometimes, you're just going to slow for the car to be able to move with the clutch fully engaged.

I understand what you're all saying The thing is that, I can give the car more gas and go at 1200rpm on first gear (out of the range where the car doesn't have enough power to move by idling) with slight throttle input and the car will still exhibit the same behaviour, just slightly go faster, then slower... I don't think I have a jumpy foot at all, I do have a driving simulator at home with gas/brake/clutch and if I want to hold a certain throttle position my foot can just stay there.

Anyway, thanks for your help, I guess I'll go drive another Mini and see if it does the same thing.

[xtremepsionic]

Quote: Originally Posted by Lawrothegreat

If you are driving forwards at slow speeds, and not using the clutch whilst moving, the slowest you can go in 1st gear is about 4mph, and in 2nd gear 7mph, in a 05 5-speed cooper (assuming my speedometer is correct!)

Yep, understood. Again, it will slightly go faster/slower with:

1. No throttle input, car rolling at idle speed, clutch completely engaged
2. Slight throttle input, car moving at 1100rpm, clutch completely engaged

[camini]

When putting car in 1 from a stand still and gently letting go the clutch the car will just smoothly accelerate and continue its journey at around 900 rpm without stutter.
MC 03
To me, if your car jerks in 1st when doing as described above, it's not a new mini - get it checked.

[Wooly]

Quote:

I don't think I have a jumpy foot at all, I do have a driving simulator at home with gas/brake/clutch and if I want to hold a certain throttle position my foot can just stay there.

Well its not about a jumpy accelorator foot, if you take your foot off the clutch quickly the car jumps. when i was learning to drive my instructor showed me goin from 2nd to 1st around a tight corner and there will always be a jump but you can minimise it to make it barely noticeable by keeping your foot on the clutch for longer. its sounds to me like you take your foot off the clutch too early i used to have this problem when learning, keep your foot on longer and you should feel the clutch push up naturally (just make sure you dont keep your foot on too long and burn it )

When you go slow in town or around traffic at like under 10 mph just slightly depress the clutch and add some acceleration, rather than, when goin slow just using the accelorator, thats where your problem is i think.

[xtremepsionic]

Quote: Originally Posted by Wooly

if you take your foot off the clutch quickly the car jumps.

Nah, thats not it, I'm pretty smooth with the clutch.

I got it checked out by the dealership today, they said they'll update the software for the electronic throttle as there is a little problem with my car.

Thanks everyone