Hoping for some direction here. I just bought a Mini Cooper S 2008, its an auto and has the turbo 1.6 motor. Soon after i bought it i noticed that it was blow black/blue smoke after idling and then taking off. I also noticed that its using quite a bit of oil (one tank and a half of gas to took the oil from max to min). My fear is that the piston rings are shot, leaking oil and burning it up causing the black smoke. I wanted to get the take of this forum on best next step. Couple of other notable points. When i bought it, the downstream O2 sensor was needed along with a cycling misfiring. I deduced that a new spark plug was needed by switching the plugs and repulling the code. I have since fixed both of those issues, and the engine light is now off. Lastly, i'm not sure if my oil pressure switch is working correctly, soon after i bought it, i checked the oil and it was almost completely out, yet the oil light wasn't on. Is that normal? Thanks in advance!

 

welcome aboard and sorry to hear about your ailing mini.

Depending on the mileage, it could be the valve stem seals and/or the PCV. you may do a compression check and a leak down test to see what's going on. Also, if the timing chain hasn't been replace, consider replacing it.

 

Do you have any history on the car? Common failure points as mentioned above are timing chain and PVC among others. Oil use and smoke may both be caused by the PCV. A compression test will rule out the top end. Hopefully the prior owner did not let the chain go and pass on the problems to you.

 

My prediction is its a combo of carbon build up on the intake valves/valve seals wearing and the PCV system. I bet if you removed the intercooler and stood it up on one end, a fair amount of oil will drain out.

Solution: Walnut blast the intake valves or remove the cylinder head and have it cleaned/rebuilt by a local Cylinder Head shop. Walnut blasting is a hell of a lot easier and cheaper than removing the head. It won’t clean them completely, but should be enough to regain lost performance and help the valves seal.

Then remove the rear PCV hose between the valve cover and the intake manifold. Plug the connections. You can buy the plugs or just saw off the ends of the hose (the one you removed) and cap them with some some JB weld or high temp epoxy; Making your own plugs.
Then add an Oil Catch Can and use 3/8” tubing or smaller between the valve cover, to the OCC, then use the same size tubing from the OCC to the turbo inlet connection.

While you’re at it, remove the intercooler and drain all the oil out of it. You can use some degreaser spray to soak it, then rinse it out with water and let dry.

 

Sam
I think I'd do some basic maintenance first & see what you've really got in a week or two. I'd change all 4 plugs for new ones - copper plugs are fine for $10-$12 a set & will last 10,000 miles or so. I'd get a good quality oil & air filter & oil filter change & then keep a close eye on the oil level - weekly at least. Always use a mid or high-grade gas.
Notes: Blue smoke accelerating = oil = rings. Blue smoke after decelerating or coasting = oil = valve guides or seals. Blue smoke after idling could be either. MINIs don't like to idle!
Black smoke = fuel.
White smoke = coolant or condensation.
MINIs like their oil! Use of a quart in 1,500 miles is not unusual. You might consider using a thicker grade such as 5/40 or 10/40 - always full synthetic & a good brand.
The oil pressure switch & light have nothing to do with the oil level. You can have a low level but good pressure, indicating that your engine bearings are good. If you have low pressure regardless of the level it indicates wear so the light should only be on at start-up & go off immediately.
MINIs are high maintenance, but worth it. Find a local MINI independent garage, there's no need to support the $$$ealer.

 

I know this might be overboard, but check your oil every time you get gas. Get a scanguage, you can have oil temp, water temp, air/fuel, boost, intake temp, etc. up on one display, 4 of them at a time. There is a thread here on how to treat a stage 2 tuned car, read that and treat her like that and you shouldn’t have any issues. I’m not stage 2 yet, close on mods, and she carves up some twisties and will hit triple digits when needed.

 

A failing turbo will also cause smoke.