I need to replace my PCV valve and probably some of the breather system components. Also, I need to look at replacing more of the vacuum lines. Both breather and vacuum lines are under the intake manifold.

Is it worthwhile to remove the intake manifold? I think it might be to get a good look at what's wrong and correctly replace what needs replacing. The manifold should be a few bolts and some gaskets.

Any advice?

 

You can probably get by without removing the manifold. Move the expansion tank up out of the way and that should clear up a lot of room to work below the back of the intake manifold.

I'll be attempting this on an AWM in the next few weeks, so we'll see how it goes.

 

I've done two (2001 A4 and 2004 A4) both 1.8T Quattro. It can be done without removing the intake. Move the expansion tank, and you have enough room to work. It's not easy, you need be creative to get the clip off the elbow into the crankcase breather, and be careful you don't break the dipstick funnel (or replace it while you're there). But it is doable. Also if you are replacing the elbow, it may shatter and pieces may fall into to the area below it. I used a flexible hose on a shop vac to remove those.