Murray recently quoted me $632.90 plus any extra fees, etc. for the walnut blast. I was half tempted to have them do it, but started researching the DIY route as well.
Bentley Manual for E9x 2006-2008 @ $62.81
2.5 HP 10 Gallon Air Compressor @ $179.99
Portable Abrasive Blaster @ $39.99
25 lbs. Coarse Grade Walnut Media @ $24.99
It would cost around $310 in parts for the compressor, blaster, walnut media, and Bentley manual, and even less when you find the tools on sale (which HFT is always holding). I'm seriously considering this route.
Matt, any tips, tricks, or gotchas that you came across while doing your cleaning? What did you use to seal off the port so you weren't blasting your own face? How did you turn the engine to seal the valves?