You need a valve spring compressor tool like this one:

Alternative

You can have it overnighted.

Here is a video that covers the procedure:


Its really pretty straight forward.

Glad you found the problem.

 

Thanks, I don't think that tool will work on a 16V, since the spring is buried in a hole. This one is supposed to work. Has anyone used it? http://www.fcpeuro.com/products/bmw-...r-kit-cta-2112

 

Here is the problem. That's what made it so hard to find the broken valve spring in the first place.

 

Sorry about that, I did not think about the S2 valves being concealed like that.

Been awhile since I worked on one.

That tool should work just fine.

Here is a pic of the factory tool.

 

Here is the culprit. I managed to create a "McGiver-like" spring compressor and install another valve spring pair. The replacement spring, from another S2 head has smaller windings, but is the same height. The inner spring appeared identical. The broken spring also has 2 red stripes on the upper couple of windings. Has anyone seen this before?