Chain Tensioner
 

I have a 2001 X5 BMW 160k miles

Last week I decided to replace the tensioner located on the passenger side engine block.

While removing it I didn't pay attention how it came out and now that I'm trying to install the new one I can't remember which side goes inside the engine block. Can someone advise? Thank you in advance.

The tensioner can only go in one way. Did it come apart or something?

Great advice!! yes it did come apart when I took it out.

Here is a good page that shows all about the tensioner. It should help you put it back together:

HowTo-> M60/M62 Timing chain tensioner replacement