Originally Posted by Kr320i
When dealing with American cars...if you have excessive blow by then it usually means the rings are going bad or the valves or serious vacuum leak. I pulled the oil cap off of the bimmer and it tried to die. Had a lot of air rushing out and I've never had that experience before. Never had a bimmer before.
If you take the oil cap off and the engine ran poor but didn't die I would say you have some other vac. leaks as the engine should die with the oil cap off. BMW uses very different cam profiles and duration than an American car. You were probably hearing air being sucked in not forced out, this is due to how the cam is. By running these sorts of cams in the BMW's BMW has eliminated the EGR system from their engines. The last BMW with EGR was probably the 1979 320i and even then it wasn't a true ERG like on an american car.
So, I would look for cracked hoses or hoses in poor condition and replace them. Like I said in my pervious post if you pull out the dipstick the engine should run poor and almost die, and if you pull off the oil cap the engine should die. It would probably be a good idea to do a major service on the car if it hasn't been done recently, plugs, cap, rotor, valve adjustment, oil change, fuel filter, diff fluid and trans fluid.