Hello,

I own a 2015 Mini Cooper S hardtop 2 door.

Saturday night I start the engine and the engine sounds drastically different than normal.

No knocking, no ticking, just louder, almost sounding like a diesel engine.

As I start driving, the engine sounds normal while accelerating, but as soon as I let my foot off the accelerator, the roughness comes back in full force.

Took it to my local euro shop here in Dallas TX and they found nothing.

My check engine light came on about 10 days ago for the fuel cap not being tight. I bought a new cap and the light went away. I mentioned this to the shop and they still said my Mini looked in near perfect condition.

I am due for a 60,000 mile service, which includes spark plugs, and they said that might fix the roughness. But they said they did not sense anything off about the vehicle.

has anyone run into this before? I tried searching and only found “rough idle“ and I feel like my issue goes further than just idling.

thank you, happy motoring

Caleb

 

Motor mount causing the engine to shake? Maybe that what you are hearing?

https://www.northamericanmotoring.co...placement.html

 

I was getting rough idle occasionally, especially after cold idle stopped. I use tier 1 gas exclusively (with factory tune) and once in a while I think that I got bad gas. Injector cleaner helped and the new plugs definitely stopped the occasional rough idle. I have had to back off of the gas pedal now, the response is quite noticeable.

 

Get the service done. If that fails to solve the issue, then try the motor mount.

60K on plugs is unthinkable given my driving style. Three Minis to date (N14,N18, B46) all trashed plugs by 30k.

Further observation: Do not assume the engine is not misfiring just because the OBD does not set a misfire code. The misfire condition code requires multiple detections to set the code.

Would really like to see pics of the 60K plugs......

 

Yep my factory JCW plug have to be done every like 30K, that's the interval for the JCWs

 

Do you have an aftermarket exhaust? I believe the decel roughness could be turbulance caused by mismatched piping diameter from downpipe to catback. I think I have a similar thing on my car. However I'm not sure if this is what you are explaining.