9 replies to this topic

[gstarMini]

Mini 30
1989

i am a super newb
lately after driving for 20 mins or so or when i reach 50ish miles per hour, when i change gear and try to accelerate it judders a hell of alot and then does pull away or hesitates. this first happened last week, and i dont know where to start looking for the problem.

thanks very much for any ideas you might have

[jwoosoo]

well if its after 20 mins then starts to happen i presume its when the engine fully warmed up, which suggests mixture and maybe choke sticking. but i'm only going by my old 998 had that issue or similar when i had it 10 years ago. but is it engine or gearbox doing the juddering? could be an oil issue at a guess. fairly newb myself so suggest you double check anything i come out with lol

[gstarMini]

well if its after 20 mins then starts to happen i presume its when the engine fully warmed up, which suggests mixture and maybe choke sticking. but i'm only going by my old 998 had that issue or similar when i had it 10 years ago. but is it engine or gearbox doing the juddering? could be an oil issue at a guess. fairly newb myself so suggest you double check anything i come out with lol

aha, well it judders as i try to accelerate so gearbox or engine i dont know :/

[LukeMoss]

Check your gaps on the spark plugs

[gstarMini]

Check your gaps on the spark plugs

i assume they need to be uptight?

[LukeMoss]

Do you have a Haynes manual?

[gstarMini]

Do you have a Haynes manual?

aha good point, ill look in that. thanks very muchly

[Cerberus]

Are you just putting your foot to the floor?
Or is this just with light throttle?

What sort of revs is the engine doing when you change into 4th?


Mine judders a little bit at 50 in 4th, but just pulls through it. We've put it down to it just being the nature of the car.


does it only happen when the car is warm?


I'd give the entire ignition system a good check over.
Spark Gaps (as suggested above)
Points gap
check all the dizzy internals are in good condition

[gstarMini]

Are you just putting your foot to the floor?
Or is this just with light throttle?

What sort of revs is the engine doing when you change into 4th?


Mine judders a little bit at 50 in 4th, but just pulls through it. We've put it down to it just being the nature of the car.


does it only happen when the car is warm?


I'd give the entire ignition system a good check over.
Spark Gaps (as suggested above)
Points gap
check all the dizzy internals are in good condition

when i ease it, then i keep it there and with ore revs it does push through it.
thanks for the suggestions!

[irish.yobbo]

So this is only after changing gears? It judders, it feels like it may be losing power, but once the juddering stops, it runs as usual?

If this is the case, I'd say clutch. Usually with clutch judder, it will happen more changing down gears than up.

First, check your master/slave cylinder operation. Have a look in the engine bay, and get someone to push down the clutch pedal. You should see the clutch arm moving smoothly. If it stops and starts as it moves, you'll have problems. You might also want to check your clutch adjustment to make sure it's engaging properly.

After that, it's probably a job for a mechanic. Clutch judder is usually caused by oil on the clutch plate, or uneven drive straps. Has your clutch been replaced at any time? If so, many people forget to machine the flywheel so that the drive straps are parallel. If they're not parallel, they can buckle and cause clutch judder.

Hope this helps.