Hello All,

First post. Lurking and searching has quickly pointed me to the correct diagnosis but I've failed to find any nitty-gritty on how to fix it. Some background: this isn't my car - it belongs to an acquaintance's daughter who is currently serving in Afghanistan. It's a 2005 (sorry, I don't know where the VIN break is for the B6-B7 so this may be in the wrong forum but it shouldn't make any difference) 3.0 A4. I was asked to look into the sudden, significant coolant leak that appeared to be from the rear of the engine. Researching it here pointed me to the rear coolant crossover pipe area which is, of course, impossible to see much of without tearing out some goodies up on top. Having now done that, I can now see coolant dripping off the bottom of the coolant pipe where it couples to the hard pipe coming from the rear of the driver's side cylinder head.

So the question is how does one remove, inspect and replace this piece? It looks like the crossover pipe is plastic. That raises the possibility of the root cause being due to a crack or deformation of the plastic along with that of a simple o-ring failure. I'm guessing I need to remove the intake manifold to get to it.

Related question - any recommendations on service literature? I see a number of electronic manuals on "the bay" (is it OK to say ebay here-some forums are funny about that?) and welcome feedback on choosing one. I recently bought one for another friend's Lexus that was excellent.

Thanks in advance!

 

anyway, an update. Yes, obviously the intake manifold has to come off. Not a bad job really, though trying to figure out how to disconnect the various electrical plugs is frustrating. Of course I broke off both of the plastic guide pins before I knew they were there but they sure are easier to extract than a broken metal fastener. So now I can clearly see that the leak is not where the crossover pipe attaches to the driver's side head, but rather where it attaches to the ~1-1/4" hard pipe coming from the water pump housing. At this point it really looks like an o-ring failure but I don't have the crossover pipe out yet (need to remove the hard EGR pipes first). It really is a busy little place at the rear of this engine.