Mini Cooper S R56 – engine woes


If you own, or know someone who owns a MINI Cooper S (R56) car, from 2006.5 to 2011, read on with great interest or concern.

With the push to get more new cars produced, broaden the product line, the life cycle has gotten shorter and shorter, and manufacturers have also taken other steps to outsource some major parts of the car to help in the rush to get this all done. Add in the change in technology, push for greater gas mileage and more power, hybrids, and there is a certain formula that something along the way may not go according to plan. We have seen this with many of the manufacturers…it doesn’t seem limited to any category or segment. Now enter MINI…and with the introduction of the second version of the second generation MINI, they have fallen in this hole. They outsourced the first MINI motor for the Cooper and Cooper S, and now have taken that same path again with the current version of the MINI, albeit with now a different engine supplier and having moved from a first version Supercharged motor to the current version Turbocharged model.

None of that would be bad….unless something could go wrong. Most of our customers today believe their car should run nearly trouble free, and not have any significant engine issues till the car nears 200k miles. Some of that is forgiven if the car is a specialty or high performance car (read Porsche and Ferrari).

The other concern is when the manufacturer tries to turn their head the other way when an obvious, and recurrent problem pops up. This is what we are seeing w the current model MINI Cooper S, the one with the turbocharged motor. Due to the size of our MINI customer base, we first started to see this issue about 2010, and now are seeing a more steady stream of occurrences. As one would expect, MINI themselves first saw the issue arise, and after a full year of issues, had issued a Technical Service Bulletin….first to its dealers, and then to the public. But, this doesn’t mean the were stating they knew there was a problem, a Service Bulletin is to make service managers and technicians aware of how to test and repair a known issue. That is how MINI positioned it, and continues to do so. Their first Service bulletin even took a more backhanded approach as it communicated the issue to the dealer network.

The issue – as low as 20k miles, and we have seen it mostly around 50k miles, the motor starts to make loud rattle. This noise is louder on cold start up, and is less noisy or may sound like a normal engine sound once the engine is fully warm. The issue is the chain tensioner….and it is not working as designed, and not producing the tension the timing chain needs, and the timing chain hits the outer enclosure and makes the rattle sound. But, that in and of itself wouldn’t be too bad, but what can happen if this is not taken care of is. If the customer doesn’t have this addressed, and this tensioner continues to get worse, and the wear occurs to the timing chain guides as well, the customer could experience complete engine failure (the chain will jump the timing chain gears, timing will get off, motor won’ t run well, valves open at the wrong time, and then really bad things happen as the pistons and valves do direct battle, with the engine losing)…read the motor will break.

There is a known fix to this, and MINI even has a test to determine if the tensioner is producing less than desired tension. Depending on when this issue is identified, and the longevity of the wear period, the extent of the fix can be minor or major. At a minimum, it requires a new timing chain tensioner (not a quick fix, but not out of the ball park in cost either). But, if the wear is greater, then several parts need to be replaced (timing chain, timing chain tensioner, gear, guides (3), and some key bolts).

If your car or someone you know has this, and the car is under warranty, MINI will test the car, and should cover the repair. If you are outside the warranty period, then even though MINI knows of this, the repair will NOT be covered.

The current TSB related to this issue is:

SI M11 02 07
Engine – February 2011
Technical Service

This Service Information bulletin supersedes SI M11 02 07 dated October 2010.

So, be aware, listen to your motor, and you may want to have MINI test your car to see that all is OK.? Believe us…this is a REAL ISSUE.


I’m updating this post (originally written by us in Dec 2011, but updating now in June 2012….as we are seeing cars at about the rate of one a week w this issue with many NOT having addressed this issue early, and producing other unwanted results…….more expensive repairs).

Here are pics of a recent example where the following occurred –

(1) The timing chain tensioner does not provide sufficient tension (you can feel a significant difference in the current motor version versus the new version)

(2) The upper timing chain guide wears through, and then breaks. The picture is of the pieces left after it has broken into multiple pieces. These pieces then fall down into the timing chain galley and do further damage…and in another recent case, got caught in the oil pump chain, and broke and stretched the oil pump chain nearly throwing that chain and causing oil starvation (which would have been the end of the motor).

(3) The side timing chain guides break into pieces, and fall into the oil pan, also requiring additional time and work to repair. The pic below shows how one case, the pieces did get caught in the oil pump chain, stretching it, and almost causing it to be thrown and killing the motor altogether.

NET – if you own, or know someone who owns a 2007 – 2009 MINI, have them get this fixed, even if they think they are FINE.


Here is a comment from another shop who has read and follows our blog, about the MINI issue –

“I work in an engine rebuild center . we are seeing more & more of these MINIs coming in every day now … burning oil & timing chain problems … new one is the top guide is wearing causing metal fillings into engine ” not what you want “. Last one causing Vanos unit (variable camshaft) to cause a fault code 287d to stop working as relies on oil pressure… not the best from BMW/MINI I must say.” …..

Another comment rec’d on March 14, 2013

This just happened to me. 68k on my 2009 S. Was running perfectly, never noticed a rattle or anything, but blam, dead car. It


  1. Merry
    Posted April 26, 2016 at 10:03 pm | Permalink

    Nevermind all those questions, today I towed the car to the dealership. and the service tech informed me that they’d found the timing chain had gone bad, more details tomorrow.

    I’ve gotten a notification of the tensioner class action settlement, and have til June to make a claim, but here’s where my questions start: My understanding is that this a Prince engine design flaw, with the chain being internal to the engine case, and that failure can happen at any time, no matter how well one maintains their vehicle. I have followed all guidelines, and exceeded them, but still have had both the clutch and now the timing chain go out. If this re-occurs after October, any extended warranty will be gone, as the car will have be in service for 7 years. I also don’t see any accommodations for re-occurrence of the failure or a fix for the faulty design. So this can happen again, and from what I’ve read, is likely. Here’s the question: does the N18 engine design take care of these flaws, and is it possible to put one in my car? Unclear to me if the design was intended to fit the pre-revision cars.

    Any info greatly appreciated!

  2. Ricardo Reyes
    Posted May 20, 2016 at 10:37 am | Permalink

    My wife has a 2010 Cooper S A/T with 54K miles and started with a heavy oil leak from the chain tensioner, we have to replace it (it was not tight properly), then she drove over a piece of a truck tire and broke the auxiliary pump that we replaced (pain in the neck)
    Today started a heavy leak of coolant from the passenger side that I don’t know yet from where is coming. We are out of town and I will carry on a AAA truck, What do you think would be the cause of the leak?, I will appreciate your help

  3. Posted June 13, 2016 at 12:34 pm | Permalink

    I have a 2011 mini cooper s all 4, 23500 miles on clock.same thing, engine warning light on. sounds like diesel engine but its petrol, contacted AA who took it to local BMW specialist garage who have had it for a week, found out today its the fuel pump which I have been told is what probably is causing this problem but reading forums this then leads to chain tensioner? I think its terrible, car fuel pump should last time of car, the warranty in America has been extended from what I can gather until 120,000 on clock why not in UK!?, why is nothing ever don here, am so sick and tired of being ripped off, have contacted Harold Krueger who is CEO I believe. Also lad earlier onsaid her is a current court case? More details please, thank you

  4. Tamer
    Posted November 2, 2016 at 9:36 am | Permalink

    Hi all
    I cant believe that at 23k miles my beloved Mini Cooper Clubman had fault code 2845 VANOS ACTUATOR MOVEMENT, OR P0015 ON P CODES. The car start up engine lumpy and out of synch as if it misfires. This will happen at idle. I reached out for the dealer and they said timing was out and vanos was not working properly.
    On further testing; there is no fault on the vanos actuator (which is the timing cog on the exhaust cam) there is no fault on any electrical components, there is a big fault in design of the cam system. For the vanos PROPERLY to work on this engine oil pressure is key, the problem is feeding oil to the exhaust VANOS. The dealer stated that there is minor wear on the cam carrier cap, which causes the bearing seal to fail, thus causing the fault code. I cannot believe that at such low mileage I was advised to BUY A NEW CYLINDER HEAD. A side note; the PEUGEOT 207 (French Car) HAS THE SAME ENGINE SAME PROBLEMS. MINI does not want man-up to this problem. I will never Trust a mini EVER!

  5. Miguel Furlong
    Posted January 5, 2017 at 5:12 pm | Permalink


  6. John Hillyer
    Posted January 19, 2017 at 8:13 pm | Permalink

    Does anyone know if some clever person has reproduced a robust N12 B16A (2007 Mini Cooper) timing chain tensioner ?

  7. Nelson Prince
    Posted February 2, 2017 at 9:25 pm | Permalink

    Is this only with the S or does the non S also have the issue with the Prince engine?

  8. Posted March 2, 2017 at 3:36 pm | Permalink

    We timing chain issues all the time. VANOS codes are cropping up more and more as these engines wear. The latest one had bad exhaust cam seals causing the VANOS code. The warranty on the High Pressure Fuel Pump has been extended to beyond the 2009 models to include 2010, 2011 and 2012. I have seen nothing issued by Mini on this but several of my customers got them covered after calling MINI.

  9. Donna Blik
    Posted March 16, 2017 at 7:49 am | Permalink

    I just had my 2010 Mini Cooper S towed into the shop last night. Called this morning and there is no compression in the engine. Seems like last year and this year will be the year to poor money into this car, first the water pump,Serpentine belt and then a some sensor thing, now this. I have read of the loud tapping noise above and mine has had that, but I have taken it in to have all my service done at my mini dealer and they have never said anything about this being a problem, call me stupid but shouldn’t they say hey, that noise there is an issue and we need to check it out? They tell me when it’s low on oil and when they feel the tires need to be changed. I have had then just go over it and do a “wellness” check if you will just before the winter, wouldn’t this have been a cause for concern for them?

  10. Donna Blik
    Posted March 16, 2017 at 7:51 am | Permalink

    Oh and in addition to my previous comment, It has just over 40k on it. I bought it new in 2010.

  11. admin
    Posted April 2, 2017 at 4:29 pm | Permalink

    If the fault was indeed related to the timing chain / timing chain tensioner issue, then, yes, they should have been able to validate that when the car was in for service. There is a very well defined set of traits / noises that are the tell tale signs of these issues. Sorry for your issues.

  12. Sunil
    Posted May 25, 2017 at 3:10 pm | Permalink

    2010 mini cooper s with rattling noise on startup for 5 – 10 mins. I debated that the should cover it , however the 2010 model is not listed in settlement. So I asked them it’s the same engine(N14) & engine parts and should not matter whether the car was assembled in 2009 or 2010. So the dealer agent has requested the manufacturer to cover it.
    The bill is upwards of 4000$. I will update if the manufacturer agrees to cover it.

  13. Sunil
    Posted May 26, 2017 at 12:13 pm | Permalink

    So the mini has agreed to do pay 75% and asked me to cover 25%. For now I asked the dealer to proceed with this deal. However I’m willing to purse legal options to get 25% back. If any of you has 2010 mini cooper s rattle noise and are looking for legal options , stay connected with me. My email is This is my secondary email.

  14. Kim
    Posted June 16, 2017 at 5:40 pm | Permalink

    Just wanted to add to the list of unhappy Mini Cooper s owners. Mine is a 2008 model covered 46,000 and is BMW garage now. Timing tensioners have snapped costing just over £1,000 so far, still not fixed so costs just keep going up. BMW UK not interested poor customer service. In America BMW have settled customers claims what is happening to all the minis affected in UK
    Thanks for any advice you can give

  15. Melinda
    Posted June 20, 2017 at 9:21 pm | Permalink

    We have recently experienced the same issue, unfortunately new engine needed at a cost of $7K and told by the mechanic to get rid of the car. We have only had the car 6 months paid $15K for the car with less than 50000 KLMs. Mini Australia have the same attitude and issue was even the cost at BMW to have the issue diagnosed at $1800 before Mini were even will to discuss GW. The car has log books stamped by BMW and always serviced regularly with correct spec oil. My issue is after repairing we now need to off load incase it happens again!

  16. Takis
    Posted July 8, 2017 at 9:27 am | Permalink

    My mini r56s from 60k gradually deteriorated and now 100k needs a kilo of oil per thousand km and when trying to accelarate looses power. Suggestions, rebuilt or change engine block? How i know the status of the next used engine? Or buy a new one?

  17. admin
    Posted July 9, 2017 at 1:32 pm | Permalink

    Sorry for your results w the MINI engine. We have moved most of our customers to another used engine, as that seems the best value, economically. We have had much better luck w the used engine, upgrading a few of the parts before going in, and also changing the type of oil used (we no longer use BMW / MINI full syn oil, we have moved to using Motul 8100x-cess full synthetic in all our customers cars). Good luck.

    Posted October 11, 2017 at 8:39 am | Permalink


  19. enea
    Posted November 7, 2017 at 7:40 am | Permalink

    From what i read here from all you lovely people’s comments, it makes me feel lucky that our mini has survived for 10 years. obviously not without frequent visits to the dealership mechanic and outside of it. But right now the timing chain issue has affected my N18 engine of my 2009 mini cooperS. And just as someone stated in this comments already, it was preceded by a failed high pressure fuel pump. It makes me mad that this amazing car has so many design problems only because of the early success Mini had and having to scramble to meet consumers demand for production. I remember when we ordered our Mini it took 7-8 months to arrive fresh of the boat. Anyway now the mini even though kept shiny looking on the exterior , the interior under the hood its a crying mess. mind you its all off warranty and the parts aren’t cheap. I didn’t mention that it burns a ton of oil which from what some one. now all i can think of doing is get rid of the car which is probably worth not even $2000. Good luck to all

  20. Larry
    Posted December 18, 2017 at 9:54 am | Permalink

    Purchased 2007 mini cooper s with 116K miles and have had low oil pressure(starts at 40 psi and drops to 5psi when hot). Changed to a dealer oil filter, replaced oil pump, checked and cleaned oil system solenoid valve and check valve. Oil pressure does not change much with engine speed. Rod bearing feel snug but may be the next replacement project. Suggestions?

  21. Scott
    Posted January 4, 2018 at 9:52 am | Permalink

    2011 MCCS with the N18 engine. I fix my own vehicles. Mine presented with oil in the water. Gallons and gallons of water. As fast as I filled the radiator, the oil pan took it all in. Pulled the head, changed the undamaged head gasket, installed ARP head studs with thread seal. Buttoned it back up and still had a massive water leak into the crankcase. PROBLEM: Freeze plug in the dead center of the “lifter valley” was missing. Looks like a normal oil passage or head bolt hole. Purchased a new aluminum freeze plug from the dealer – found out it was a piece of junk and would pop out again the next time I did not properly bleed the thermostat housing. SOLUTION: I machined up a threaded aluminum plug; threaded the hole; torqued it down with epoxy in the threads. WARNING TO CONSUMERS: Customer should pull the valve cover and look for that freeze plug (or missing freeze plug). Procedure: Pull the VC and start adding water to the radiator overflow tank. If you see water moving amongst the valve springs, follow the water flow to the (missing) freeze plug.
    The presented problem was water in the oil, which usually means that the head gasket is blown, or the “engine is blown”; or the valve cover is bad. A mech can tell any story to the customer and they will be forced to believe it. After the customer agrees to a massive repair bill, the mech fixes the freeze plug in 10 minutes and pockets a huge profit.
    Other problems with water in the oil: The oil pump cannot move aerated oil (whipped chocolate milk). The French “fuel efficient” oil pump has an electric solenoid inside that is fitted with a fine screen that won’t allow aerated oil to pass. These parts must be flushed/cleaned: Timing chain tensioner, oil pump; turbo oil lines and turbo oil passage, oil pan, water pumps; possibly the turbo air pipes. After reassembly, must change oil&filter after 5 minutes of running, then change again after 10 minutes of running. Change the water at least twice. This extra work is easily 5 hrs labor and $200 in oil/misc. A shadetree mech can do this work.

  22. wendy
    Posted January 23, 2018 at 7:28 pm | Permalink

    2009 mini cooper s
    89k miles
    replaced fuel pump under warranty 2016

    no death rattle yet, but valve cover and gasket replaced, pressure sensor, both upstream and downstream O2 sensors, still pops codes 296a and 2b64, thinking its timing, but hear whirring/hissing sound when clutch is engaged.

    im scared to own it after reading this.. plus it was at mini and they never said anything.

    idle rich, engine light on, codes 296a and 2b64.

    looking for air leak now..

    need to unload this money pit fast..

  23. Posted March 15, 2018 at 9:37 am | Permalink

    I have done quite a bit of research on the timing chain issue. (I own three second Gen JCWs, one N14 and 2 N18’s)

    I have currently fixed three Cars, one being my own with the following relatively inexpensive fix. Replace the timing chain tensioner ($60 part). (the tensioner failure applies more to the turbo cars than the naturally aspirated ones (N12)).

    Here is what is happening with these cars. For various reasons, oil burning, leaks, inability to measure engine oil level correctly or lack of timely oil changes (I recommend oil is changed every 7,000 miles and not wait for the oil change light which can activate with higher mileage which is a generally shared consensus in the community) the engine requires a certain level of oil due to the hydraulic nature of the Vanos system and the hydraulic chain tensioner. The tensioner has an internal spring, and is also boosted by oil pressure. Over time the spring fails or breaks (and makes a lovely crunchy sound when depressed manually) which seems to be aggravated by dirty or low oil. Once the tensioner is weak it allows slack in the chain usually manifesting at initial startup but then as oil pressure builds the engine will quiet down. Over time as the tensioner gets even weaker the engine will start to rattle more. This is due to the chain slapping the plastic chain guides, and mainly the upper guide due to the slack now induced by a weak tensioner. If this isn’t addressed eventually the upper guide will break causing plastic bits to fall into the oil pan and accelerating wear of the other two guides and also causing chain stretch. Chain stretch also occurs with a lack of lubrications or with dirty oil as it causes the chain to wear faster. Once the chain has stretched or worn past a certain point the tensioner can no longer apply the correct amount of tension. The fix for all of that if allowed to get that far is a complete new timing chain cassette… tensioner, chain, sprocket, bolts, guides.

    Here is the good news, all of this occurs downstream of a failing tensioner. The current newest version can last 40K, 60K, 80K… it all depends on multiple factors but the biggest one is probably related to frequent oil changes, proper oil level and the type of oil. I use redline synthetic and have for years in many cars. It’s worth the higher price. My old R53 had oil pressure of when it was new at 120,000 miles…I attribute that to the oil and the frequency of changes. Oscar made it to 80,000 miles before I changed his tensioner, and he’s a modified JCW (N14) with 260 hp. So make sure you oil is always at the proper level, and change the oil at no more than 7000 miles, regardless of what the oil service indicator says. But to avoid all the bad stuff that comes after your tensioner starts failing…change the tensioner! It’s a $60 part. Changing one is a lot like changing spark plug. Removing the boost tube is the hardest part to gain access to it, or it can be changed from underneath with a wobble bit or u-joint extension. Every Mini I have fixed by replacing the tensioner was caught early enough to prevent damage, I went a bit further in that I used a tool ($60) from BMW to measure chain stretch confirming the chain was in spec, and pulled the valve cover to inspect the guides, but this is because the cars were already making noise and I wanted to be sure. Most people can accomplish this themselves with simple hand tools and a little mechanical aptitude. (Buy the Bentley Manual, it will pay for itself in short order). But the no brainer part of this fix is change the tensioner before it fails. It’s a $60 part… did I mention its only sixty dollars? So budget that into your maintenance routine. Change the tensioner every two years, that’s $30 a year, plus keep the oil topped up and your car will likely make it to the 100-120K mark before needing the complete timing chain replaced. You can get cheaper versions of the slack measuring tool on Amazon (less than $20 if my memory is correct) which is simple to use and can check for stretch every time you change the tensioner giving you a heads up before a very expensive repair is needed.

    So that is the fix I have come up with, that to date has worked on every car I have I have tried it on and I’ll bet it can save all of you a lot of money and grief. Now it would be nice if the Prince engine wasn’t so sensitive to lack of maintenance and oil level and the tensioners were better designed (they are now with the latest versions), but it is what it is. The MINI is still the most fun car I have ever owned, and I love the camaraderie of the MINI community; Like a friend of mine said, “it’s the only car that comes with friends”. But I think most will agree that replacing a $60 par every two years is a small price to pay for keeping your MINI running healthy and strong.

  24. JefSharpe
    Posted April 17, 2018 at 8:20 pm | Permalink

    I have a 2009 MCS turbo with a bad number 3 cylinder showing zero pressure during compression test. Other 3 showed 90-95 pounds which still seems low. Can this be due to a stuck valve from carbon buildup?

  25. edith thompson
    Posted August 3, 2018 at 5:11 am | Permalink

    i brought a 2009 mini cooper from NETTO MOTORS in west palm beach,fl.paided $6200.00 dollars cash,the owner told me when they get a vihicle,they go through it with a find tooth comb before they sale them to anybody,but to make a long story short.i had the mini towed to north carolina and about a week later i put insurance on the mini,drove it about 15 miles and oil light came on,i had it towed to a mini dealer and they said the engine was shot and there is no way that they could have not known,i called them and they said-you brought it as is…dont believe nothing these people tell you because they will lie when you confront them.even the mini dealer i carried it to said–these people knew that the engine was damaged in the car,they said there is no way they shouldnt have known,and other words they said the car had been doped up to last for a little while…NETTOMOTORS,be carefull if you buy from them.

  26. Kevin Guy
    Posted August 20, 2018 at 4:23 am | Permalink

    Hi No compression in cylinder one, added spoonful of oil in to cylinder 1 still no compression, no blue smoke from exhaust pipe when fired up, hardly runs though! cylinders two, three and four are reading approx 145, engine is the N12 1.4cc with approx 90k on the clock, removed valve cover found top chain guide broken no sign of plastic guide, valves appear ok just looking from top not sure about seats etc. Do you think its just the timing out causing the no compression or deeper trouble with valves , seats , guides etc.


  27. admin
    Posted August 26, 2018 at 2:59 pm | Permalink

    First response would be just timing is off.
    But, normally, if timing is off in one cylinder, then all cylinders should be experiencing the same thing.
    Good luck. Bruce

  28. Posted September 4, 2018 at 5:19 am | Permalink

    I went over this website and I think you have a lot of great information, saved to favorites (:.

  29. Colin
    Posted September 23, 2018 at 1:36 pm | Permalink

    I have just sold my 2005 Cooper S, so fitted with the supercharger, it had 120k miles on the clock and I had replaced the timing chain, followers and tensioner at 80k miles. I regularly changed the oil, fully synthetic and used it as a daily commute,220 miles and several track days. The car never failed and the engine in standard form was a brilliant track day car. Just don’t mention ABS faults.

  30. Posted September 28, 2018 at 2:06 am | Permalink

    Over 11K spent less than 2 years ago for a car that is now worthless.
    Mini Countryman 2011 started to make an engine noise / rattle out of the blue taken to dealer who never warned us about this issue and suggested we would be better to buy diesel as would easily go for about 200K! Only done 60k miles! expensive diagnostics and now told 4 k to repair. What a rip off just want it gone now and will never buy Mini again…….

  31. bill
    Posted November 5, 2018 at 12:26 pm | Permalink

    I feel the pain of those who have experienced timing chain issues and other woes which have been well documented in the r56. However, my ‘08 cooper S (now at 102,000 mi.) has been completely reliable, and I have been fortunate to have dodged the major issues which have been described. At 75,000 miles mini offered to inspect and replace, if needed, the timing chain. I was having no issues, but when the dealer checked it, the chain was “ borderline” and so it was replaced, along with the tensioner and guides, without charge. It was unfortunate that it took a lawsuit and too many years for mini to step up to this problem, but they finally did step up.

    From the time I purchased my car I did not believe that minis recommendation of extended oil changes made sense ( and it turned out not to, at least with the Prince engine) . I have changed the oil and filter every 3-5 K miles since new, and I I think that this very important in preventing tensioner, turbo and valve carboning problems.
    Also, using Tier 1 gas may be beneficial as well.

  32. James R Artzner
    Posted January 11, 2019 at 12:58 pm | Permalink

    I just bought my first MINI, discovered that the center freeze pug in the head is junk. I bought it with what I thought was a blown head gasket, so I rebuilt the entire motor with top shelf forged and studded parts. Drove it 12 miles and the dumb machine shop put the old plug back in it and it pops out again? Now its got a true blown head gasket and who knows what else is screwed, its knocking like hell. I put the correct plug in and was hoping I would get lucky, buy no deal. Any answers or comments that you could share for some help would be great.

  33. Posted February 12, 2019 at 6:23 am | Permalink

    Hi, would you care if I share your post with my mastermind group?
    There’s a lot of peeps that I think would like your website.
    Please let me know. Thanks.

  34. Ray Banicki
    Posted April 17, 2019 at 8:17 am | Permalink

    OK, so here’s my saga. I filled my 2008 R55S with 87 octane Shell. Normally not an issue if you’re not running at full boost, right? Well stupid me forgot and got into a ‘Take no prisoners’ combat mode situation. 10 minutes into it #3 piston was having no part of the foolihness and decided to depart, laving the battlefield to her 3 sisters. So a full set of piston, rings, standard sized con rod bearings, screws, etc went in and all should have been honky-dory. Had substantial difficulty…impossible actually.. rotating the crank. Naturally I attributed this to my practice of using white lithium on crank jouirnals. Removed rod caps, flushed bearings & journals then proceed to use Mobil1 0-50 as pre-lube. After re-assembly engine fired right off, running fine, making no odd or rude sounds. About 2 minutes running time I thought I heard a light tap when lightly bringing revs up 22-2800 revs…sounding like a classis con-rod knock to my ear. Hmmm..odd that since journals were as perfect could be and oe bearings were as new. Before installation I compared bearing sizes and overall dimensions, but not thickness. I mean, why would I…they were new and marked with STD,

    Stethescope provided no help in isolating or locating the double light rap/knock. Un plugging #1 coil eliminated all knocking, confirmining my intiuition. Drained oil came out as clean as it went in. Removed sump, popped #1 rod cap and found bearing shells had rotated to 90 degree position..meaning split was at 12:00 and 18:00. OK, so I blamed myself for not securing shells in rod and cap securely. and installed another new pair of KING inserts on #1, and a new pair of rod cap screws. Fired her up as before…silent for 2-3 minutes..then the dreaded double tap/knock resurfaced, at the same rev range.

    Sump came off again, oil looks clean and clear. When pulling #1 cap it seemed torque might have slipped a bit, but that may just have been my imagination at play. Again, sinsert retotated to the same 90 degree position. So, any ideas…like could it be the inserts are incorrectly sized due to them not being OE? Has anyone else encoutered a similar issue? Causes? Personally I’ve never ever seen a crankshaft bearing without locating insane design. At the moment I’m giving serious thought to making several indexing marks in both rod and cap by means of a hardened punch, then applying a coating of LockTite red to those surfaces before re-assembly. Any remedies, solutions or thoughts anyone?

  35. Posted April 26, 2019 at 1:15 am | Permalink

    Thanks for sharing superb informations. Your website is so cool. I’m impressed by the details that you’ve on this blog. It reveals how nicely you understand this subject. Bookmarked this website page, will come back for more articles. You, my pal, ROCK! I found just the info I already searched everywhere and just couldn’t come across. What a great website.

One Trackback

  1. […] Mini Cooper S R56 – engine woes – BR Racing Blog – SERVICE Alert. If you own, or know someone who owns a MINI Cooper S (R56) car, from 2006.5 to 2011, read on with great interest or concern. With the push to get more … […]

Post a Comment

Your email is never shared. Required fields are marked *