Last weekend my 2010 Clubman S threw a P1497 and P0302 code. I noticed the very slight oil leak on the back corner of the valve cover had become the Exxon Valdez around the oil fill cap and coil pack for cylinder 2.

The engine was idling very rough at low RPM and was puffing blue smoke out the tailpipe. I didn't see any obvious crack so I replaced the valve cover and cleared the codes.

After starting the car, the P0302 came back so I checked the plug and it was very fouled with oil and carbon. Figuring an air leak in the valve cover could have been causing a rich condition I replaced it and reset the codes again.

To my great disappointment, the rough idle at low RPM returned along with a slew of codes. P0302, C342D, P0055, C3064.

I've seen some postings about P0055 being related to the O2 sensor, but nothing definitive. I've also seen some threads saying the P0055 is related to the cam sensor which scares the !@#% out of me given I've been running a Manic Stage 1 tune for the past 2 years. I can't find anything on the "C" codes other than it being chassis related.

I'm thinking a compression test on cylinder 2 is in order to see if there is a valve or spring issue. I'm also thinking of replacing the first O2 sensor as maybe it has become fouled like the spark plug (not sure if that even makes sense).

I'm looking for some advice on next steps. I've pretty much exhausted my mechanical knowledge and the Bentley manual at this point. I haven't found an independent mechanic that I trust.

 

So was the cyl 2 plug covered in oil again? It pretty much sounds like compression and leak down test time. Before that if you can get your hands on spare coils and plugs ,try that. A full set not just 1 and 1. Sometimes you have other cylinders misfiring as well but it will only read one.

 

Lambda sensors aren't cheap, I wouldn't recommend buying one in the hopes that it fixes the problem. The most common reason for failure is due to oil ingress from either sloppy oil changes, or leaking valve covers over a long period of time.

Start by cleaning the oil out of 2, making sure the plug isn't getting oil fouled, you may have a failed coil pack due to oil, clear all the codes and see what returns, try running the car without the tune and see what happens, reset the adaptations, etc.

 

Thanks for the suggestions, I wanted to post an update.

I swapped the coil pack between cylinder 1 and 2, still got the P0302 code. So I'm thinking it's not the coils. When this started I put to tune back to the stock map which didn't impact the behavior.

One thing I forgot to mention is my catch can went from being nearly empty to 1/3 full after a few days of driving so I did 2 rounds of seafoam treatments and got a lot of black soot out the tail pipe. I still have the P0302 code plus P0300 now. Idling is actually better but the engine is struggling to start.

I'm taking it to a Mini specialist tomorrow recommend by a tech at the dealer. They are going to do a leak down test and check for carbon buildup. I'll let you know what happens.

 

The fouling on the plug appears to be mostly carbon. I'll post a picture but its hard, sticky and black. A little bit come off when I sprayed it with carb cleaner, but it's definitely not just oil.

The rest a the plugs looked normal.

 

Here is the fouled #2 spark plug:



Amazing how this black stuff can form and the engine still start. The coil pack looked normal, no oil, soot, or discoloration.

 

Looks like the issue is a failed fuel injector in cylinder #2. The injector is stuck open which is dumping fuel into the cylinder constantly causing a very rich condition.

Initial compression test was good but they couldn't do a full leak down test due to fuel in the cylinder. They did a smoke test and compression was perfect. They said I probably didn't do fatal damage to the engine because I parked it right away when this started.

They are going to replace the failed injector and inspect the intake for potential carbon buildup (and do a walnut blasting if necessary).

The post-cat O2 sensor throwing a code and is likely coated with carbon like the plug, so I'm going to replace that myself because they want way too much for a simple job.

 

Oh yeah with a plug like that definitely check the injector. Glad your car is back on the road.

 

Wanted give a quick update for anyone following this thread...

Cylinder 2 fuel injector was replaced which solved the super rich misfire condition. They found (and cleaned) significant carbon buildup in the ports for #2, but the rest were clean.

After a spirited test drive last night, #3 has a misfire now. 😞 They quickly rotated the coils and plugs but #3 still misfired. More to come...

 

Compression test confirmed the worst, almost zero compression in cylinder 2. The rings are toast and the cylinder wall scored. The damage is terminal. They think so much gas got into the oil it acted as a solvent within the cylinder washing away all the oil.

I'm in a state of shock right now that a driving a short distance with a failed injector ruined the engine. Going to drag it home tonight and figure out my next step.

 

Sorry to read this. Very sorry.

 

Thanks for the kind words! After getting several estimates to replace the engine, I've decided to trade it in because the numbers didn't make sense.

While it's a huge disappointment to give up a car I've loved, I found a nice used 2012 Countryman All4 S that will better fit my family and still give me something fun to drive.

I'll be selling my N14 mods soon if anyone is interested.

 

I had a bad injector that was stock open. although i did not drive the car at the time, but i used to have it running for minutes and minutes and push the pedal close to the metal. after finding the culprit and driving the car, the catalytic passed out, so I got it replaced. now after two weeks to long distance driving, everything is good. Mind you, I do all the work by myself. if you ever want to rebuild that engine, send it over to philly.