Vacuum Pump / Brake Booster Pump O-ring replacement

[McDonaldD]

Sorry, replying without reading much of the work history: before you try anything else:
1.) replace the oil filler cap and the o-rings on your dipstick.
2.) an oil change using BMW's new recommendation of 0-40W, which goes against the 5-30W recommendation in the manual.

Based on what I've read of your history:
3.) Vanos solenoids mount through the timing covers and can be replaced without much effort (each solenoid is held in place by one small hex bolt and metal clip, remove the clip and wire - pull the solenoid head outward. I was careful and seated the head of screwdriver on a non-sealing surface of the solenoid and then levered each one out. I have done this many times, helping others and such, and seems to be the easiest way. You only need to get the solenoid to "release" and then it can easily be removed - they're about 6" long.
4 - 11367546379 O-ring - VANOS - Small (Green) Size: 21,29X1,78 $1.85
4 - 11367513222 O-ring - VANOS - Large (Green)Size: 35X4,0 $2.08

4.) Throttle body gaskets

5.) Intake Manifold gaskets - Both gaskets, like ~$12 each but would like resolve your issue by just replacing the intake manifold gaskets

6.) Timing Covers and Valve Covers - The big job - takes 2-3 days - if you know what you're doing

My job eventually encompassed the entire top sealing surfaces of the engine - Both valve cover gaskets, both upper timing cover gaskets, vanos gaskets, throttle body, and the intake manifold (fills with oil). But, because it was convenient, I rebuilt the the coolant system: water pump, thermostat, coolant hoses; replaced the drive belts, belt tensioners, idler pulleys; replaced the spark plugs; and changed the oil. Obviously, a lot of this stuff is unrelated to the blue smoke...but you’d basically have to do the job over again if one of these parts were to fail in a few weeks, months, or years.

The timing cover gaskets cannot be swapped out by themselves because its top rim is part of each valve cover's sealing surface - it needs to be done at the same time as the valve covers.

1 - 11147506424 Gasket Steel - Passenger Side Upper Timing Cover $12.02
1 - 11147506425 Gasket Steel - Driver's Side Upper Timing Cover $12.02
(1 - 11667509080 O-ring - Vacuum Pump - Passenger Side ~$4.52 - you've done this one)

Valve Covers

1 - 11127513195 BMW Gasket set, cylinder head cover ZYL. 5-8
1 - 11127513194 BMW Gasket set, cylinder head cover ZYL. 1-4
4 - 12141748398 O-Ring for Camshaft Position Sensors Size:17X3 ~$1.20
2 - 11127518420 sealing - Eccentric Sensor Gasket ~$5.69
1 - 11128507153 (if leaking - likely, yes) Cover lid - Oil Fill Cap ~$7.78
6 - 11367507729 (Optional - I had 1 fail)O-ring - non-return Valve 9,5X2,5MM $2.92
8 - 11127570219 (Required if cracked/damaged) Spark plug tube $27.00/ea