Great write up. This DIY led me to diagnose my fault code that came up this week. Thanks for posting it.
The Bentley manual suggests switching the positions of the solenoids as a test to see which is bad (this doesn't make sense if code 2A82 is intake and 2A87 is exhaust). The manual also says the solenoids can be cleaned with shop air, which is what I did. I also used CRC Electro Cleaner to clean them up as well.
Also, the engine cover does not need to be removed to get to the solenoids (at least on the N52 engine). You can get to them with the cover in place.
One last tip. I suggest removing and replacing the solenoids one at a time. If both solenoids are out, it is very easy to accidentally drop one of the small mounting bolts into the openings, which would be really bad since the screw would now be in the casing for the cam chain drive. If I may augment the procedure a bit: I think it is best to remove and replace (or clean and replace) the bottom solenoid first. Then remove and replace the top solenoid second. Following this sequence will prevent accidentally dropping a mounting bolt into the front of the engine.
Last edited by ENINTY; 06-11-2011 at 07:36 PM.