I am trying to salvage what I can and do what I can do on somewhat of a budget to get my 2009 Cooper S not misfiring to then sell. I work a ton lately and don't have much time to wrench. Though now will have to just to no lose a bunch.

Backstory:
Purchased the car back in Sept 2020 with 128k miles from a decent size dealer. Radio was the only thing not working. Ran and drove fine. I bought it. Drove it home 40 miles then made another trip the next day and had no issues. Car sat a week then noticed the rattling sound. Sent off to Wedge Kyes Motorwerks in Baton Rouge, LA. The local BMW dealer who sold the car new said we do not work on MINI's at all nor sell them. Our mechanic recommended them and seems they are the only specialist around my area. They changed Timing Chain, tensions and all that stuff along with Valve cover and gasket. (Have to look to see if they changed PCV Valve or if it normally is included in the cover.) Paid $1600 for that. Drove home fine.

The very next day started the cold start issue. Purchased a Ancel BM700 scan tool so I could read codes. It was a bunch of codes and ended with a 2880 High-pressure system code. The codes at the time were a 2B5C,2786, 2745 and 2880. Since I just had the repairs done and didn't know if it was a vacuum leak from valve cover I brought it to the shop. They performed a smoke test and determined no leaks. They changed the HPFP and feed line and cleaned throttle body. They recommended the replacement of the MAF sensor. Drove 40 miles home fine. Even drove the next day 80 miles no issues.

Week later started running a tad rough. I checked the history and was like well its been awhile since plugs were changed and they were changed frequently on the history. I ordered 4x Bosch 028851111249 coils and 4x Bosch 9710 ZR7S1332S, and Seafoam SS14 top engine cleaner. Changed the parts and had a misfire detected on cylinder 1. I did not have it torqued correctly. Cleared codes ran the car awhile and it no misfires detected. Sprayed in airbox below the MAF. I think I may have did it wrong because it smoked just a little. Drove the car 15 miles and check engine light came on. Stopped and checked and it was for 28AA Bypass blow-off valve plausibility. Since that was the only code I figured it was not a critical thing but would be on reduced power. Drove it 200 miles and the light would come and go.

Week later it started the super light white smoke at idle and also spitting oil out the exhaust at first start of the day. On the concrete it had this soot stuff with oil. I started seeing a pattern where at first crank it sound one way then right at the time of the small amount of white smoke there was noise. Maybe a tick from something. It did this every time after give or take a minute after cold start. So I drove the car and it would puff a small white smoke at take off. I checked for oil in coolant and also water in oil. Nothing out of the ordinary. Just noticed high consumption of oil and some oil blowing out of exhaust at crank.

Month or so later some small trips here and there started noticing small puff of blue smoke at take off. It was still doing the small white smoke at idle but then was a bigger puff of blue at take off. I think near the end it started a definite lifter tick sound. I placed Lucas Pure Synthetic Oil Stabilizer to top off the oil level. I figured well I prob have a valve stem issue now plus lifter noise issue. I ordered Royal Purple 5w30 HMX oil and K&N filter. I let the car idle with the Lucas and it took some time but the smoke issue eased but the lifter tick stopped. I drove it 40 miles and checked oil and it was darker so the additive was doing something. (I am not a fan of additives cause they aren't designed to fix worn engines but more of get by a little longer.) The next weekend I had the first oil change since owning the car. After the oil was changed the smoke did return and then the lifter tick noise. Drove 40 miles home.

The next day I drove it 30 miles and on the way home the car then threw a CEL and then a blinking engine light on the dash. If you pressed the gas the whole car would shake but would eventually hold speed enough to get home. I checked codes and it was showing P0300 Random/Multiple Misfire Detected, P0301, P0302, P0303. I pulled the plugs, Cylinder 1 had some oil on the plug. Cleaned it and installed it back. The others looked fine and reinstalled them. Ran datastream to see the misfires and it was now just doing it on Cylinder 3. I took plug and coil from Cylinder 1 to Cylinder 3 and ran car to check misfires and was no change. Though...when I pulled the spark from Cylinder 3 there was a small particle on the metal part of the electrode. (It was on the part that would be closest to combustion chamber.) It crumbled in my hand like sand. I then ordered a replacement MAF sensor from eBay and installed it to see and it actually threw a code for it and still misfires on the same cylinder. I then threw up my hands since I could not keep investing into the car. Then whats strange is that the ticking noise and light white smoke at idle is not happening.

I am at a complete loss now. The two mechanic invoices alone almost was the same price as the car was purchased for. I am trying to do what I can on a budget to maybe get the car running enough to sell. I prob will have to order parts but if its burnt valve or something bigger I am not going to want to invest the money. Don't know if the car has ever had the carbon cleaning on the intakes. Any help is appreciated.

 

Compression check? If low, leak-down test to find out why? When was the last walnut-blast on valve stems done --- in miles, not weeks / months?

 

In my opinion, must replace engine valves seals and clean the Vanos actuator.After that do a complete Vanos adaptation.Try first with vanos actuator , it is usually stuffed with burnt oil deposits.

 

I do not know if the car has ever had a intake cleaning procedure performed. The history doesn't say anything about the intake or anything cleaned or even inspected. So prob will say never been done.

Ah... vanos actuator cleaning - Now that I will check to clean and inspect.

 

I agree with OBW that a compression and leak-down test would be a good next step. My 2010 MCS at 127k miles was burning oil at a quart/500 mi AND it was spitting oil out the exhaust at startup. I put new valve stem seals in it hoping that would do the trick. It did not. I melted a hole in #3 piston a couple of months after replacing valve stem seals.

I also don't like the fact that you found debris on the electrode on plug #3. All that oil being burned in the combustion chamber contributes to detonation which can lead to bad things...

Hopefully you're engine is healthier than mine was.