You’re only seeing the surface.

Our most active car forums and technical guides are reserved for registered users.

Sign up here to get total access and start sharing your own ride.

Mini bucking at low speeds

The go-to spot for all non-technical car talk. Whether you’re discussing the latest EV tech or classic steel, park up and join the conversation.
Post Reply
Benny_Cornwall
Posts: 46
Joined: Mon Feb 02, 2026 9:05 pm

Please assist me in resolving an issue that has recently arisen; I have only just joined. Last nite, I did some hard acceleration and briefly hit the rev limiter on my 2017 F57 JCW, which has a 6-speed and 28K miles on the clock. Despite the absence of any warning lights and the engine's normally smooth operation, it is now idling poorly. Even with my OBD2 and Bimmercode app, I was unable to locate any error codes. Following the online advice, I have disconnected the battery for 10 minutes, tightened and retightened the fuel and oil caps. The one problem I've encountered so far has been with the back brakes' malfunctioning sensor.

I would be extremely grateful for any assistance.
Top
Benny_Cornwall
Posts: 46
Joined: Mon Feb 02, 2026 9:05 pm

https://www.amazon.co.uk/s/?search-alia ... Cooper+JCW
Top
MMCGARAGE
Posts: 58
Joined: Mon Feb 02, 2026 8:58 pm

My issue is very similar, but it becomes much worse when the engine gets hot. My diagnostic revealed a misfire on cylinder 4 in my 2013 Mini Coupe Cooper, which has 159,000 miles on the odometer and is powered by an R58 engine. My posts will provide some recommendations for things to look at; maybe they will be useful to you as well. I'll be sure to monitor your post for any updates.
Top
Benny_Cornwall
Posts: 46
Joined: Mon Feb 02, 2026 9:05 pm

I appreciate the feedback and will look over your thread to see if it provides any answers. A crankshaft pully / harmonic balancer slip might be the culprit, according to my Google search. At the moment, I don't have many specialised tools—if any at all—so I'm trying to figure out what needs fixing so I can either do it myself or bring it to the dealer, which is going to be painful.
Top
MMCGARAGE
Posts: 58
Joined: Mon Feb 02, 2026 8:58 pm

It may be out of my reach, but I'm hoping to get myself fixed, too. It will still hurt my wallet, even if I can get away from the dealer and use a recommended expert.
Top
Davey_NC_US
Posts: 3
Joined: Wed May 13, 2026 5:05 pm

It is becoming increasingly difficult to identify and repair issues with these vehicles, even with the necessary testing equipment, and to identify and fix such faults.
Top
Benny_Cornwall
Posts: 46
Joined: Mon Feb 02, 2026 9:05 pm

Hi everyone, I just returned from dropping off my Mini and I had two problems. The first was a problem with the lower engine mount, and the second was with the harmonic balancer, which had to be redesigned after a design failure. Starting with the original, installed version might be a good place to start if everyone is experiencing the same problem.

I appreciate everyone's responses to this thread and will share pictures of my progress so far once I get my baby back.
Top
Post Reply

Return to “General Motoring”