Hello eveyone, we have a 2012 Mini Cooper S Countryman | R60 | N18 bone stock with 58K miles. We bought it brand new, not used.
We checked with the dealer where we bought the Countryman from and there is no recall or extended warranty (wanted to get this out of the way so its not referenced).

Here is a short summary.

To the point, PCV system failed. Found the PCV membrain was cracked, and the valve cover gasket needed replacement as too much oil was going into the intake. I did not think to install an OCC because the car was bone stock, not tuned, and fell for the trap that BMW had improved the PCV system on this Gen of Mini. I have always owned BMW cars that are tuned and have a OCC. This was our first Mini Cooper though, and it was intended to be a grandma driven car.

After changing the PCV membrain and Valve Cover Gasket, the oil intake reduced significantly, and back to normal. Two weeks later performance issue with the car cutting power mid throttle again( ie too much oil in the intake system fauling the plugs). Removed chargepipe to tourttle body and a tone of oil came out. Checked intake side no saturation of oil, so thought it might be resideual oil that was left in the intercooler. Clean out the oil before the TB, cleaned the plugs and moved on.

Two weeks later performance issue with the car cutting power mid throttle again and this time low boost code. Pulled the chargepipe to the TB, and again a tone of oil comes dropping out. Checked the intake side no oil saturation, PCV system is working as should. One last place to check was the hotside of the turbo, pulled off the pipe and there is a lot of oil saturation. No oil coming in but a lot of oil going out of the turbo.

Check compressor wheel, there is absolutely no play, couldnt even turn it(?). Im convinced its a bad turbo, is it worth rebuilding or what else could be causing the excessive oil since its apparent an oil seal failed on the inside IMO(?). Any thoughts? Thanks in advance.

 

By hot side, do you mean that you pulled the exhaust downpipe and found oil there?Or the pipe from turbo to intercooler? I am chasing a smoking issue myself and after replacing the valve cover, I still have a ton of smoke, so I'm trying to determine whether I should replace the turbo or valve stem seals next. It could also be a restricted turbo oil return line, which also requires turbo removal.

 

The chargepipe going to the intercooler from the Turbo. Was able to monitor boost via OBDII software and the Turbo is not producing anyboost at all. The higer the acelation the more negative boost reading. First thought on this when I tried to turn the compressor it would not budge. So time for new turbo or to see if can be rebuilt if its something minor. Whats boggling is this car is baby driven.

 

Just updating this thread. Oil starvation from sludge build up on the oil feedline to the turbo. Period of time of oil change intervals need to be shorten to about 5k miles since the car is baby driven 5 miles day, 4-5 days in a week. Hope this helps

 

Thank you for the and update and good to hear that you found the cause.

Did you have a lot of smoke from the exhaust?
Did the smoke improve immediately after you replaced the PCV membrane?

And you replaced the whole turbo and lines to fix the issue, correct?
Did you go with new or used turbo?

 

Sorry about the late reply to this. Wanted to wait for final results, and when I got the car back.

There was not enough sludge build to have cause oil starvation to the turbo to seize up like it it did, in fact no one can really say for sure unless the old turbo was broken down. This wont be done till I send it in to be rebuilt. We know one thing for sure, oil was blowing by the turbo shaft and going back into the intake line, and in addition the PCV system failed and was blowing oil back into the intake due to too much crank case pressure(although I replaced the PCV membrane). Not even an OCC or oil catch would have have saved this but it would have given a better red flag. Not only did I have to replace the turbo but also the entire valve cover in which the PCV system is initergrated into.

The first symptoms of PCV system failure is sharp power cuts similar to a missfire, when pressing the throttle(no fault codes are triggered). What caused this was during throttle input a significant amount of oil enters the intake manifold and then fouling the spark plug(s) upon driving. This is also noticable when you pull the plugs and they are drentched in oil or have carbon build on them expecially after a short period of time from changing them.

I can see why its recommended to just replace the entire valve cover. Short story, the problem started with the PCV system failing, leading to excessive crank case pressure.


1)Yes there was visable smoke, and oil coming out the exhaust

2) I found the orginal membrane was torn, but replacing it did not resolve the issue as the entire intergrated PCV system in the valve cover failed.

3) I bought a complete OE turbo replacement kit from FCP Euro

4) Brand new OE BornWarner turbo

 

Thanks again for the details.

After new parts were fitted, did the smoke disappear almost instantly or was it smoking for a few minutes still before it cleared?
I know it takes a while to burn out the oil in the exhaust, but just trying to gauge how quickly it happens as I'm trying to determine my next move.

 

If you flushed out your entire intake system including intercooler, then after a few minutes it will burn up as there maybe oil the the exaust system lingering. If you did not completely flush out your intake system you may have tons of oil in your intercooler and this will take even longer.

Days later if your still smoking you got an issue. I am going to post the final inspection report after the work was done. The tech that worked on my car worked for BMW, and he is no stanger to mini cooper.

"During engine operation, observed severe intermittent driveability symptoms including rough idle and lack of power. Loud whistling noises from engine and oil visibly bubbling past valve cover gasket. Removed engine oil cap while running to measure crankcase pressures and found extreme positive crank case pressure as a result of an obstructed crankcase vent valve. Excessive crankcase pressure is causing oil to blow past seals and gaskets on the engine and turbocharger. Necessary to remove and replace complete valve cover assembly with integrated CCV/PCV. Oil leaking from internal turbocharger seals as a result of obstructed crankcase ventilation is causing oil burning and buildup of carbonized oil in the turbocharger and requires turbocharger repair or replacement. Technician notes possibility of other seals/gaskets (ie front or rear main seal) being compromised by extreme excessive crankcase pressure and may require additional repairs."

Hope this helps, I learn a lot oafter paying $4k on a something the dealer could not resolve just before the warranty ended. Will be fighting Mini on this. Not expecting anything but a try.

 

Thank you again. Very helpful to see the notes. That is essentially my diagnosis as well and why I replaced the valve cover.

I may just pull the turbo and replace with a known good turbo and see what happens.

And I just changed the oil and now I'll have to dump it. :(

I didn't want to let the smoke show go on for too long in front of my house or I fear some neighbour is going to call fire dept! 😄

 

Hello, your report is very complete, thank you. One question, you haven't mentioned it, but at some point did the low oil pressure light come on suddenly and then go off? Or did it never come on?

 

yes, sometime back before the turbo failed low oil light did come on. However same day I put oil into it.