Engine running weird when hot

[BLM06]

Hello everyone, got a 116i m sport n43b20a. Had it for about 3 months and soon after buying noticed a wierd problem. When cold the car would run perfectly, however when warm or stuck in traffic you could feel it become a little bit rough, sort of a banging feel from the engine which you can feel through the car. 
 

When doing this, when driving it runs perfectly. However when you attempt to pull away, the car will drop to around 400rpm and pull away a bit bouncy, having to give it more accelerator to prevent it from stalling, whenever in reverse it does this and normally leads to stalling. Over the last 3 months it hasn’t gotten worse but it does the pulling away thing when it is cold now. Had a service >1k miles ago with plugs. Also had it smoke tested and no signs of any leaks. Does anyone have any advice or had a similar story? Cars on 161k

Thanks

[Greydog]

Morning Billy

You need a diagnostic session to narrow things down, at 161k I would also carry out a compression test and check fuel delivery and pressure.

Your symptoms could be an accumulation of things or as simple as a dying throttle body diagnostics will help

Dave