Good day everybody. Glad to join the group. Fell in love with Mini when I rented one in Germany many moons ago. Actually the exact same model down to the color as the one I own now. I have a black 2010 S N14. Purchased in Kansas City even though I live in Chicago(Amazing how difficult it is to find a manual).
I joined because I have some mechanical as well as upgrade questions. Here is a list of what I have had done since I purchased it with 70,000 miles. It now has 77,000 miles.

New tires
Fixed drivers heated seat
oil changes of course
thermostat housing and thermostat
oil cooler seal
turbo oil line
coolant flush
brake fluid flush
new intake manifold(old one was slightly melted so the car overheated at some point
replaced almost all engine sensors(2 MAP, solenoid, crankshaft, and 2 oxygen)
new valve cover
new spark plugs
high pressure fuel pump gasket
Walnut blasted intake
Nm air charge pipe

And here are my issues that I'm trying to resolve. Slight vibration at idle and poor mileage(17-30mpg).

OBD live data shows upstream oxygen sensor(O2S11) bounces between -.01 and .01 which I believe means super lean as it is supposed to be between .45 and .50.
downstream sensor(O2B1S2) stays pretty much at .80. I don't know what it should read and cannot find the answer in my Bentley manual.
There is a oily foam under my oil cap which only goes away after long highway drives. It is not on the dipstick and the coolant level hasn't changed so not a coolant leak.Any advice or opinions?

 

You don't say how many miles are on it. It looks like you didn't change the coils, bad coils can cause vibration at idle, but then so can a vacuum leak.

 

I have checked the coils and they all fire perfectly. I am wondering if the oil on the threads of spark plug 4 indicates enough of an air leak to cause my symptoms.
Plus my crankcase measurements have me stumped. For details I am using a digital manometer attached to a tube through the oil fill cap.

 

out of curiosity, have you checked the timing, not necessarily for this issue ?

 

I haven't checked the timing chain and do not know how but it is has been the highest thing on my mind and pretty much the only thing I haven't replaced so far since I bought the car.
I was wondering if the timing chain being off could cause my issues. I believe it makes a ticking noise but it is diffiuclt to tell.

 

Take a video of the sound. These engines are direct injection so its possible the "Ticking" you hear is actually just the fuel injectors doing their thing. If its a constant tick tick tick tick similar to say a type writer then its normal.

 

All my questions above are still valid(frothy oil in oil cap, odd crankcase pressures, low mileage) plus I am adding a link to a video of my engine running to get opinions if the timing chain is going and could possibly be responsible for said issues.

 

That sounds like the normal direct injection noise. Timing chain will normally start at first crank from a cold start. The odd crank case pressure could be a bad PCV. The frothy oil could be nothing more then condensation if your not loosing coolant or it could also be a symptom of a bad PCV

 

Loose timing chain will make an extra rattle just under 2000 rpm especially at cold start and/or 2nd cold start (start engine without getting engine warm, then start again). The extra sound will be very obvious.

 

Alrighty. Did two more tests.

Tested brake booster pressure at the clip by the crankcase. Maxed out my gauge at 28inHg and did not move with throttle. Doesn't sound good to me but no idea really.

tested engine vacuum by unclipping an unknown u-shaped hose under the intake manifold on the drivers side of the throttle body. Right next to where the PCV hose goes into the throttle body. Used a plug that fit well but not sure if it was air tight. Got a constant 15inHg. Dropped quickly to zero with throttle and then up to 20 before returning to 15. I am at sea level.

 

Blocked the PCV ports and added a BSH catch can on the turbo side and get 20inHg vacuum at the intake manifold. Don't know what else to do about poor mileage and rough idling so I will replace the timing chain with a Detroit Tuned setup next week.
Also purchased a new OBD reader, NT301, to make sure my old one wasn't giving bad readings, but nope. New one gets the same readings.
o2b1s2 at idle .80
o2s11 at idle -0.01 to 0.01

I am almost positive my car gives no warning lights on the dash when there is an isuue. Had an obvious misfire and nothing popped up. Not with aggressive driving or normal driving. What could be the cause of this? I mean it was bad enough to make the car feel like the clutch was slipping under WOT. Also got no code or indicator from removing the rear brake pad sensor.

 

Sounds like you're hearing the vacuum pump when you open the oil cap. If you unplug the line going to the pump it should go away. A hand full of people have remote mounted a vacuum pump somewhere else in the engine bay to get rid of that noise.
Here's two posts about it:
https://www.northamericanmotoring.co...mp-delete.html
https://www.northamericanmotoring.co...mp-delete.html