We own a used 2010 Mini Cooper S Hatchback (r56). Just found out this model year had 2 different engines, looks like I have the n18 engine. Bought with about 66,000 miles a little over a year ago and it now has about 75,000 miles. Daughter drives the car as we bought it for her, and of course, she loves it, and I think it is one of the more fun cars I've ever driven, including my 1981 Corvette.

The car has used oil from the getgo, which is of some concern, but not too heavily, maybe a quart in 2000 miles, so I did not lose sleep over that. There are oil leaks around the valve cover and replacing the valve cover was on my list of things to do. I smell faint burnt oil smell after the car has been driven and while driving it, so oil is dripping on exhaust manifold it appears, also there is a very thin film of oil buildup on the underside of the hood which is more evidence of a leak and burned oil. There is soot around the inside of the tailpipe, black carbon like soot but no oil was noted.

Yesterday, was checking oil level, was down about 1/2 quart, and went to add oil and noticed the view down the oil cap hole was alarming, really nasty brownish sludge buildup. Car runs decent. Started vehicle and removed oil cap to look for oil movement, it idled rather poorly then and nearly stalled with oil cap removed.

Here is a pic:

sludge viewed thru oil cap hole

I do NOT recall seeing this scary view before, and I change the oil myself and check it regularly since girls (daughters and wives) are very guilty of not checking oil. I believe I would have noticed this ugly view before either while changing oil or adding oil, or to say the least, I would be really surprised if I had missed this, been a diy mechanic for nearly 50 years.

The car runs decent, but not tip top, a little sluggish imho as if a vacuum leak exists or the electric motor on the accelerator is a bit slow. No DTC's at this time.

Could this sludge be evidence of a bad PCV valve?

All informed comments or tips are welcome.
This is my first post, if I did something wrong or posted in wrong spot just advise, thanks.

Kyle

 

1st, I think you have the N14. I don't think the N18 hit the S till 2011. Also, with the coil wires going forward by the oil fill cap that looks like a N14. The N18 coil wires go away from the oil fill cap. If you got a larger view of the engine, I could confirm.

I do not have any oil leaks on mine, 2012 Coupe S with a N18. It was using 1.5 - 2 quarts per 5000 miles. I replaced my PCV and after 1000 miles, my oil level hasn't hardly changed. Not sure if this is your issue, just letting you know what I have experienced. If I understand it correctly if the PCV is geeked up it can create pressure in the engine making oil leak from "weak seals" or bypass the rings and burn. It might be worth a try if it is as easy as the N18 was.

BTW, my Chevy Avalanche started using oil about two years ago. It was the PCV as well but, no changing it. New valve cover at the dealership installed about $1000.

 

Yea, thats pretty bad, I have 125K on my n14 and dont have that build up. Owned since it had 18K.

You have an N14, dont use oil cheap oil from Getgo, Use a top teir oil (Liqui moly, Genuine MINI..etc) and change it every 5-7K miles. Don't let the oil level go down below the lowest point, this causes the oil light to come on and you can get chain rattle also when very low.

Valve cover has the built in PCV, and if not functioning correctly it can burn the oil. If its not the valve cover its the valve stem seals that tend to leak and burn oil. I would also check to make sure you have had a carbon cleaning on the valves.

I would pull the valve cover off and have someone clean as much as that out. Be careful not to get the crude in the oil return. Also get an oil flush and change it to catch the rest of the residue. LiquiMoly proline engine flush is what most people use here. If you replace the valve cover then you dont have to clean that.

Same engine but on a Peugeot.

https://www.nomaallim.com/de-sludge-...nder-head.html

 

Changed the valve cover out with a rockauto recommended cover, the new one rattled when shaken, the old one made no noise when shaken, gonna do a post mortem and open up the old one for inspection and I suspect the valving components might be clogged up or defective.



The inside view of valve train area was not near as bad as it looked thru the oil fill cap hole, see attached pic. I cleaned it up some but not extensively, a vacuum would be the best device to clean this up but I do not have one to suck up oily sludge. After cleanup I poured a quart of turbo engine flush from makers of Gunk over the interior of the head with a rag blocking the falloff into the bottom of the engine (near the timing chain area), but I note there are multiple drain holes thru which the fluid disappeared down into the head, installed now valve cover and did the 5 min run time flush and got a puddle on the floor, hrmmmm. Maybe a 1/4 cup of liquid on the floor.

After draining/replacing oil/filter, went out for a drive seems to run a bit better, less sluggishness. My only concern is the puddle on the floor. Oil was pretty full when I added the quart of engine flush, but where would it overflow from? Maybe oil pan seal bad? After a 15 min drive and parking car for hours had a small spot on the floor now, maybe a 1/2 teaspoon of oil or less at the most on the floor, wiped it up and looking to see if this was from flush time leak (very runny oil) dripping off engine/oil pan still or do I now have a new leak where before the leak was small and never hit the floor, if there was al leak before it hit exhaust and burned up and did not spot the floor below.

One other point to note, wow was that valve cover stuck to the top of the head. I had to pry like hell to get it off, old gaskets were hard and almost seemed they were glued in place tho no glue-like residue could be seen, maybe the gasket melted to the head and valve cover? Do ya suppose it got to hot at some time in the past as I've never seen such a gasket failure. Heck my old Buick Riviera had 20 year old valve cover gaskets that were still very pliable and flexible when I replaced them.

Thank you to those who responded for taking the time to respond or comment.

 

Be careful that the VVT solenoid doesn't get clogged up with that engine flush. the flushes can liberate chucks that will clog that little unit.

Looks like the last owner didnt change their oil often enough.

 

My friend, my car's name is "The Oil Leak". So many places for oil to leak from. Oil cooler, turbo lines, front main seal, oil pan, vacuum pump...start poking around.

 

Sounds like something is up with that rockauto valve cover, should not rattle. Maybe valve cover is leaking now?

My guess from the lack of oil changes/ consistency and maybe some hot heat cycles to the valve cover it baked it in place. Those gaskets can get pretty brittle with heat cycles.

Keep changing the oil and flushing after short periods to get that junk out.