Wow this thread is so confused.  Some people think you are talking about
the rocker arm covers (valve covers most people call them) and are
wondering why you would want to drill holes in them.  Others think this
is about aircooled tin which of course you should never remove or modify
(unless you want to shorten your engine life).

We are talking about the push rod tube covers under the engine.  These
are actually stainless steel to start with only the tabs that go to the
exhaust flange is plain steel and does rust.  I have seen these covers
rust before too but it is rare.  Stainless steel will rust and certain
versions are more prone to it than others.
Unlike an air cooled engine, these covers do NOTHING to cool or warm the
engine.  They are there to protect the push rod tubes from sticks and
stones (the ones that can break your bones) flying up and puncturing
them.  I have driven vans short distances with these off to check for
leaks and have never had an issue and I have had customers come in with
these removed by some previous shop who knows how long ago with no
issues.  However it only takes one rock or stick hit to cause a bunch of
damage so they are worth installing and replacing if yours are bad.  The
idea of drilling a hole in them to access the coolant drain plug in the
bottom side of each head is a good one.  Not sure why they didn't do
this in the first place.

I hope this helps clear up this thread a little for those who are trying
to glean some knowledge from it.

Ken Wilford
John 3:16
www.vanagain.com

Mike S wrote:
> At 03:37 PM 9/10/2008, Mike Collum wrote...
>> Mike S wrote:
>>> Feel free to argue with Bob Hoover -
>>> http://bobhooversblog.blogspot.com/2006/11/vw-engine-paint.html
>>> BTW, it applies to both valve covers and push rod tubes.
>>
>> Don't overlook the fact that Bob Hoover's article is about "Air
>> Cooled" VW engines ... not wasserboxers.
>
> Don't overlook my earlier post.
>