I just got my first bmw 850i, and have a few questions. The power steering is making some noise, i assume i just need to add some power steering fluid. Unfortunately i dont have the manual and dont know how high i am supposed to fill it in that cylindrical resevoir. Also, it says the oil needed is pentanol.. Do i have to use pentanol specifically, or will another standard fluid work. Id rather not have to get it from BMW.
Its also having some problems overheating when at a stop, idling, but fine while driving. I know that the electric fan is working. Could this be a failing water pump? Thanks

sorry, mistake. The fluid is pentosin (7.1).

Most parts stores have the fluid but it is about twenty bucks either way.

try ebay on the fluid......have gotten it there for $11 a liter........on the coling it sounds like your fan clutch is toast.........try the rolled up newspaper test to stop the fan when running........if it stops easily fan clutch is gone...

Agree with PumpedTSi. Use Pentosin and the heating issue is possibly the fan clutch. I had the same issue. A very easy replacement (1 hr max).

Fan Clutch Test (http://www.e31faq.com/attachments/att98.pdf)

The filling procedure for pentosin is easy. with the car turned off, pump the brake pedal repeatedly until the pedal becomes hard. It should take between 20~24 pumps. Then open the top of the pentosin resevoir and see the level. The pentosin level should be halfway of the metal mesh screen and be of emerald green color. Fill as needed to get to the halfway screen level and do not overfill. If the pentosin is any other color then it may be time to replace the fluid.

Ill let you know what i find after i test it. Thanks for all the help.

Yep, the "rolled up newspaper" test worked very well. I could basically stop the fan at the hub with almost no pressure, and when i let go, the fan was very sluggish going back up to speed. I guess its time for a new clutch, thanks for the advice.