The car shakes at idle?

I would start by checking the spark plugs and the engine compression. Here are the spark plugs you should use and a guide to help you do the compression test. This generic guide will help walk you through the steps for the spark plug change with instructions below for your car.

https://www.2carpros.com/articles/how-to-change-spark-plugs

and

https://www.2carpros.com/articles/how-to-test-engine-compression

You can rent a compression gauge for the auto parts store for cheap or free. Check out the images (below). Let us know what happens and please upload pictures or videos of the problem.

I once uploaded a video. It's a 2006 diesel 730D and a user here had the same problem. Error code in error memory is: 4BD2 Ars Torque Limitation.

Here are screenshots of the user I mean.

Yep, that is not running correctly. I would test the engine for vacuum leaks when it is cold only.

Here is a guide to help:

https://www.2carpros.com/articles/how-to-use-an-engine-vacuum-gauge

Please go over this guide and report back.