I'm a new proud owner of a beautiful Dark Blue 2004 545i. I purchased the vehicle for 1,500 cash. I'm currently replacing VVT components to get it back to its full power strength being that it's in limp mode. Any help would be great. I own my own basic tools . DIY has always ran threw my blood with all previously owned cars.
This one has been my biggest challenge to date.

 

Welcome to the other side.

I'm assuming you have an OBD2 reader already something you will definitely need to work on a BMW. I am also going to suggest getting INPA and the BMW tools. It's free but it you will need to put it on a windows laptop or tablet. You will also need a K+D can cable. This will allow you to troubleshoot and program bad modules. Having the correct error information are important is important when working on a BMW. You can easily spend $1000 for something a $50 part could of fixed. Generic codes are good but BMW specific errors are a lot better. There's a lot of information here so use the search tool. I'm sure your issue has been covered.

 

Get all the BMW codes and knock them down 1 at a time. Try not to get discouraged. BMW's can be tricky but you just have to be trickier.