The oil change on the CS is rather interesting:
Oil is to be changed every 6K miles by the way!
(and the oil change is a huge mess!!!!)
The CS runs a semi dry sump system which means that the engine barely contains any oil and that most of it is inside the frame (hence you get grilled when in rush hour during those 100F days)
There is a drain plug for the frame which is shown in the picture, then there is another one on the bottom of the engine sized 24mm and further more the oil filter sits on the right side just above the sprocket. You have to remove the sprocket cover and then 3 more hex torx bolts to remove the oil filter cover.
The official oil change kit from BMW contains:
Oil filter cover gasket
several copper rings which you wont use
Replace the oil drain plug copper ring, the frames copper ring and the rubber gasket (if never replaced any of those in 18K miles)
Ride the bike so the engine is warm, engine oil that is warm will flow better!
1. Remove the torx bolt shown in the picture to drain the engine oil from the frame, unscrew the oil cap up top to make sure no vacuum is created. Watch out as the engine oil will shoot out from the frame with force!
Drain the frame
2. On the bottom of the engine is a 24mm 6point bolt. Remove that bolt to drain the engine oil from the engine. There wont be much in it at all.
3. Get your torx set and remove the sprocket cover on the right side of the engine. Once removed slowly loosen up the 3 torx bolts that are holding the oil filter cover on the bike. Once you have each bolt turned 3 times slowly pull on the cover to break the seal. Oil will now slowly drip out from the underneath the oil cover and run down towards the bottom of the engine and eventually drip into the oil pan. BMW shops use a "special tool" which is basically a tray made out of some huge beer can to move the oil away from the engine block and let it run down the tray.
Remove the old oil filter and use a clean towel to clean out the oil filter housing.
4. Install the new oil filter and inspect the rubber gasket; if it looks good, it will most likely be still good. I've never replaced one in several oil changes.
Bolt the oil filter cover and the sprocket cover back up.
5. Reinstall the engine oil drain plug with a new washer or the old one again. Inspect the copper washers for unevenness if they are straight reinstall them. If reused the same copper washer since 21K miles for frame and engine.
Also reinstall the frames drain plug and do the same copper washer inspection.
6. Filling the bike back up with oil can take some practice: The bike basically holds 2.4L of engine oil or 2.5 quarts!
Overfilling the engine will cause oil to be inside the airbox which is messy!
The manual calls for filling the frame up with 1.5L or so and then starting the bike up. I usually fill her up with 2.2-2.4L of oil and then crank the engine.
You will have to check the engine oil after you have done an oil change! The engine oil checking procedure is as followed:
Run the bike so it is warm: Ride the bike! Did I mention that you really need to RIDE THE BIKE?!?! Like ride for 20mins or more! The oil has to be warm inside the frame, not inside the engine. You are measuring the oil level in the frame. With the frame being cold the engine oil will be cold and your reading will be inaccurate!
Park the bike but let the engine idle for ONE MINUTE to see if the fan comes on. If the fan doesnt run yet, let the bike idle until the fan comes on.
Turn the bike off and wait an additional minute.
Now get a clean white towel and place the bike vertical, unscrew the oil dipstick and wipe it off.
Take the wiped off dipstick and sit it on the top of the threads without screwing the dipstick back in.
Remove the dipstick and immediately place it onto the white towel: Based on the impression on the towel you should be able to see what the oil level is!
The oil level needs to be in between the MIN and the middle mark NOT MIN AND MAX
Oil level to be in between || and Min!!!
If you think that you need to add oil, its probably high already. Check your oil level again after a ride. I never had to add oil to the CS at all. Heck, even with 2,4L it was overfilled sometimes