Do the coolant pipe and alternator gasket too?
 

In the while I'm there department.... 2005 4.8is N62, 117k, new to me. I'm doing th valve seals, front timing gaskets, water pump and hoses. I don't have a leak from the water pipe or the alternator, but I hear they are common. Are they so common that I should go ahead and replace them while I'm there, or should I wait until it is a problem. That is for the advice!

I haven't done this job... but I would were I going to. I'd also probably do the alternator housing gasket.

OMG if you have the vehicle ripped down to this level then by all means do the coolant pipe repair and alternator. Why give the potential reason to go back in their at a later date?

Cost and time. It is a lot more work for the alternator. And the pipe repair isn't cheap, or I don't think it is. Have done these repairs? If so how long did it take? Just curious how much more I'd be taking on in hours. Thanks for your input!

Understand your situation but If it were me and my X I would just have to bite the bullet and do it. The rate of failure at this part of the engine is very high.

Water pipe isn't to hard a job if you use one of the aftermarket pipes. I prefer using the one that has the snap rings that engage and lock the pipe in the expanded position. I've heard about people having issues with the threaded ones and have seen them fail prematurely. The alternator housing gasket is a little more work to get to, you aren't really working around that area of the engine based on the repairs you are doing. Also depends on how much you tore down to do the jobs you're doing. The more you tore down the easier it will be to knock these two out.

To second the point made by X53Jay4.8is, if it were my X and i tore it down I would do it. When I bought it my X the coolant pipe hadn't been done, I was in school at New York and it let go when a good friend was driving it. Had it trucked back down to GA where my indy did the job for me. When my sister got her N62 545i we did a complete 100k service as well as all the gaskets including the alternator housing gasket and the water pipe. They're both known issues with this engine so may as well handle them now.

Ok and thanks for the input. Do you recall the manufacturer of that pipe? It isn't the AGA one is it?

I have seen a threaded AGA pipe fail before on a customer vehicle. When I pulled it apart it looked to be installed correctly and like the seals failed prematurely. Other Indy shops we work with don't really like using them, mainly because they are a little on the pricey side. I use the Uro Collapsible Pipe Kit, its installed in two of my families three N62 vehicles including my X5 and I've has no problems with it since it was installed around 30k miles ago. The Uro Collapsible Pipe kit is the one that uses snap/lock rings to secure it in place.

Ok thanks! Great input.