[SaltyNC]

Andy, it sounds like our cars were manufactured at the same time. I had 30K when I bought mine, and now I'm up to 49K. I would highly recommend doing as Matt suggested and do the entire vanos rebuild while you're in there. Raj at Beisan is an awesome guy. His kits address all of the known failures in the Vanos if your exhaust hub tabs are still intact. If you purchase all of Beisan's kits, it will be $450 after the cores are returned, and that will give you the anti-rattle, the oil disk with the smaller holes to prevent future exhaust hub tab failure, solenoid fix, seals, sealing plate upgrades to Viton, etc. You also need the upper chain guide and there are some washers that go along with it. All of the BMW parts needed are listed in the Beisan S54 procedure guide found on his site. If your tabs are already broken on your exhaust hub, you will need to either replace that with an OEM exhaust hub, a Dr. Vanos cryo treated hub, or you can get Dr. Vanos D300 or Turbotoy's hub with the beefier tabs. If you go with the beefier tab hub, then you would use the original oil disk and not the Beisan.

Some ideas on cost...
So, if you do all of the Beisan kits and your hub is intact, you're looking at ~$450 after core refund. If you also get his inexpensive tools, you're basically looking at $1000 upfront (including tax and shipping) with $450 coming off after core exchange of the solenoid and oil disk hub.

You also need some BMW parts. If you are changing your oil at the same time, you're looking at ~$350 including the oil. This varies a bit depending on if you plan to replace the valve cover gasket and other seals in that area. The $350 will get you the better spring set/plate that was designed for the S65, all of the various washers, replacement gaskets, chain guide, etc. and it includes a $45 shorter alignment pin that is needed on the Z4M. Your indy may have that pin or fudge it with an allen key or something similar, but it's something to keep in mind. The indy will also need the timing bridge, but they probably have that. If not, it can be rented.

Labor is interesting. I've seen a lot of variation here. I had one guy quote nearly $7000 for everything. LOL I had another indy tell me $600 for labor, but the overall quote was $4K. That $4K quote did include an $800 exhaust hub. Another quoted $800 for labor, but parts were only about $880 including a full oil change kit. So, you can imagine the one that I preferred. :-)

I see you're listed as Houston, TX in your profile. Best of luck with the recovery down your way.

Salty