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Discussion Starter · #1 ·
Hi folks,

As it looks there is almost no thread online with a misfiring N12 or N14 that is fixed so I don't have a lot of hope.

My engine lacked oil pressure so it was rebuilt by myself, head was done by the machine shop, block honed, new rings, bearings, everything.


The issue was that it always kind of ran rough on idle, you could feel it a bit but it could definitely be heard at the exhaust, it would skip a few strokes. Long story short, wideband O2 was shot but the previous owner "deleted" the O2 fault code. Flashed ECU back to the stock file and replaced O2 sensor and the "misfire" was gone.

The other misfire that was previously also present is unfortunately not gone. It happens only when you push it too hard or when the coolant temperature passes about 106C. Then it will run very rough at idle on 3 cylinders until the fan starts as usual at 108C and cools the coolant down, then it suddenly starts idling as usual. It looks like it is temperature dependent as it will always start running right when it cools down at about 90C

It never triggered any code for the misfire but it will trigger a 287D Vanos inlet actuator movement fault, but this is very rare.

Plugs are replaced with OEM ones, coils swapped between cylinders but the misfire is static to cylinder 3. My only other option is to move the injectors but I am not positive that this could be the issue.


Whenever any valvetronic engine develops a misfire I think it's time to just leave it alone, as far as I heard in most cases it is a issue with the cylinder head. I also heard about a couple of cases where nothing would help but a head replacement.


Does anyone have any idea?
 

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inlet camshaft would be my first thought with the vanos fault code what they do on oil starved engines is to wear the inner edge on the camshafts and this bleeds oil pressure away from the vanos and throw that code, as you said it need full rebuild also the oil pump dont take dirty or low oil at any point thats also effects the vanos,
as for misfire and you know for sure everything is the engine was built back right, leaves a few things to try, first off injectors swap the misfire one with a a non misfire cylinder run it see if fault moves, do same with coil packs ,
 

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Discussion Starter · #3 ·
inlet camshaft would be my first thought with the vanos fault code what they do on oil starved engines is to wear the inner edge on the camshafts and this bleeds oil pressure away from the vanos and throw that code, as you said it need full rebuild also the oil pump dont take dirty or low oil at any point thats also effects the vanos,
as for misfire and you know for sure everything is the engine was built back right, leaves a few things to try, first off injectors swap the misfire one with a a non misfire cylinder run it see if fault moves, do same with coil packs ,
I forgot to add that the head was completely shot, camshaft bearings were almost seized.

I bought another engine As-is and it turned out to be in perfect condition, looking from the cylinder bores, bearings and everything looked like a pretty low mileage engine, the internals were very clean, looks like a short oil change interval was used. I used only the head from this engine.

Another thing is one of the VANOS solenoid was full of metal shavings, the other one had no screen on it. Before rebuilding I think it had a code for the exhaust vanos, and I may have swapped them around when I assembled the engine. My first thing regarding this would be to swap the solenoids again, maybe one is just bad.


The misfire could be a bunch of things, but I thought someone experienced the same temperature-dependent misfire like me.
 

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id solonoids have metal on them chance are vanos sprocket sticking maybe got tiny bits of metal in it, would do a oil pressure test when engine hot 106c see what you got, i've seen engines before that looked perfect to find the one thing that made owner scrap car was their lack of checking the oil and had once ran out of oil and red light on dash then its to late, can normally tell by the impacted big end bearings ,
 

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Discussion Starter · #5 ·
id solonoids have metal on them chance are vanos sprocket sticking maybe got tiny bits of metal in it, would do a oil pressure test when engine hot 106c see what you got, i've seen engines before that looked perfect to find the one thing that made owner scrap car was their lack of checking the oil and had once ran out of oil and red light on dash then its to late, can normally tell by the impacted big end bearings ,
Yes, that's probably what initially happened.

Everything has been rebuilt, crank machined, new main and rod bearings.

Pressure is okay.

I thought that these engines can not be fixed to stop consuming oil. I drove about 15000km, 5000km oil changes with OEM oil and filter. Not a drop of oil consumed. At least for now.
 

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these engines cannot be stopped using oil when get worn past 50-60k due to crap bmw oil control rings ie flexi nitride and run better with solid ring sets, all the cars I have rebuilt are same dont use any oil unless get beaten then they all use it tad as goes out the pcv system , i've helped a few people on here that rebuilt them and ran in to same sort of issue with timing vanos and most ended up being a oil issue side, ie common is the oil rings on camshaft and they wear the end of camshaft away, new camshaft was how they fixed it or from a know good engine,, another thing is people have fitted after market or worn out vanos sprocket back on and they stick, also poil control solonoids fail and they fit after market cheap £25 ones and get all kinds of faults,, must use genuine only, i buy mine from Peugeot psa dealers ship, vanos sprockets are same £58 a pop, oil solonoids around £60 a pop, camshafts are expensive ,
if you take the end cap off the camshaft and run nail over where the rings sit on it and have a ridge i would say thats your issue with vanos as when the inner wears it allows the rings to spin and wear the outer case of end cap and head surface,, i have in past got away with new camshaft and a better non scored end cap before,, bmw what they find these engines they say fit new head and camshafts end of,
 

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Discussion Starter · #7 ·
these engines cannot be stopped using oil when get worn past 50-60k due to crap bmw oil control rings ie flexi nitride and run better with solid ring sets, all the cars I have rebuilt are same dont use any oil unless get beaten then they all use it tad as goes out the pcv system , i've helped a few people on here that rebuilt them and ran in to same sort of issue with timing vanos and most ended up being a oil issue side, ie common is the oil rings on camshaft and they wear the end of camshaft away, new camshaft was how they fixed it or from a know good engine,, another thing is people have fitted after market or worn out vanos sprocket back on and they stick, also poil control solonoids fail and they fit after market cheap £25 ones and get all kinds of faults,, must use genuine only, i buy mine from Peugeot psa dealers ship, vanos sprockets are same £58 a pop, oil solonoids around £60 a pop, camshafts are expensive ,
if you take the end cap off the camshaft and run nail over where the rings sit on it and have a ridge i would say thats your issue with vanos as when the inner wears it allows the rings to spin and wear the outer case of end cap and head surface,, i have in past got away with new camshaft and a better non scored end cap before,, bmw what they find these engines they say fit new head and camshafts end of,
Yes, I have fitted solid Mahle revised rings. Three piece ones with two thin rings and one wavey one. These also seemed to fix the issue on VAG TSI engines
 

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Yes, I have fitted solid Mahle revised rings. Three piece ones with two thin rings and one wavey one. These also seemed to fix the issue on VAG TSI engines
ha ha thats where I use them as well rebuilt many tfsi and tsi engines and cure the oil issues as well, MAHL do pistons that are forge grade really strong for the cooper s engines the rings sets also fit the factory pistons , that said that link I gave are very good, always get 190psi compression after rebuilds on mini engines ,
remeber the first time a tried to use the genuine bmw flexi rings rebuilt the engine was on my car and i done a load of mods on it and found on over run when hot would give a big cloud of white smoke when throttle on at bottom of a hill ,, i one day on way home got so angry at that bloody thing i rung it neck all way home,,,,hmmmm not always home before it had blown the skirt off back of piston and bent the rod as well ,, one of those days where kill or cure it then will no for sure what was wrong lol,, was down to oil coming up past those silly light nitride flexi rings and swamping the piston, so pulled it part again fitted new piston and these rings sets and we rolling roaded it after 10 miles from rebuild and got 240bhp at crank ,, taht car is still on road comes back to me once a year for service and dont use much oil when cained and zero when driven low revs,
 

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Discussion Starter · #9 ·
ha ha thats where I use them as well rebuilt many tfsi and tsi engines and cure the oil issues as well, MAHL do pistons that are forge grade really strong for the cooper s engines the rings sets also fit the factory pistons , that said that link I gave are very good, always get 190psi compression after rebuilds on mini engines ,
remeber the first time a tried to use the genuine bmw flexi rings rebuilt the engine was on my car and i done a load of mods on it and found on over run when hot would give a big cloud of white smoke when throttle on at bottom of a hill ,, i one day on way home got so angry at that bloody thing i rung it neck all way home,,,,hmmmm not always home before it had blown the skirt off back of piston and bent the rod as well ,, one of those days where kill or cure it then will no for sure what was wrong lol,, was down to oil coming up past those silly light nitride flexi rings and swamping the piston, so pulled it part again fitted new piston and these rings sets and we rolling roaded it after 10 miles from rebuild and got 240bhp at crank ,, taht car is still on road comes back to me once a year for service and dont use much oil when cained and zero when driven low revs,
That's amazing. Every bmw with these low friction rings has the same issue, starting from M54 BMWs. Never understood why they did this.
 

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That's amazing. Every bmw with these low friction rings has the same issue, starting from M54 BMWs. Never understood why they did this.
they call it evolution and i call bmw and vag and many other car makers all sat in same room one day and drafted up game of play ie if they all fit equal rubbish then customer has no where to hide thats my theory ,, i remember back in the 1990s when bmw and vag went to war over its diesel engines , vag had that 2.5tdi cambelt motor good engine came out of t4 as such they even shared it with volvo good motor and bmw had its 2,5tds 6 pot that well i had a few of them and could not kill them even after 230k still going strong,, so while they pushed each other to be better was all good built to last, then came the years of sharing engines and parts to save money so you end up with same faults crossing many brands, you also get the obsession with making cars light so reduces emissions ,, then there's the making a engine run as lean as possible without melting it down ie there is a point where a engine makes peak power to air and fuel 14.1 on petrol engines the only things that prevents it from lean outs is more fuel to cool the cylinder down,, but on these low friction tech engine with coatings this while engine is fairly new works ok and allows for a surplus of engine oil to help cool the combustion down,, so when they do the emissions and mpg etc it looks ike the engine dose really good mpg but reality is part pof the power gained is from low friction and oil allowed to apss and be used as fuel very slightly.. can you remember in F1 Ferrari got caught burning over 5 litres of oil by this process it ,meant that it could run less fuel technically reality was they could gain longer run time on 100kg of fuels and burning oil as well ,, also a bi-product is better controlled lean out so dont melt the motor down ,, its all about emissions and how fast out of warranty it will kill off the engine is my belief these days as its getting worse the newer stuff is getting to a point where its near impossible to repair half the time,, rebuilt a audi s1 a while ago thats standard 240bhp it was mapped out to 340bhp real weapon that had a injector go south after 50k and melt a hole through the piston and take out the valve seats in one cylinder ,,, the breaker wanted £4500 for the 20k engine he had and said he sells every one with in a week or two as common they do fail,, but for car owner things will get better when battery tech gets better as they just dont seem to have many parts to break ,, glad i'm at the age where i should see the last petrol and diesel cars go and that will be me retired
 

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Discussion Starter · #11 ·
they call it evolution and i call bmw and vag and many other car makers all sat in same room one day and drafted up game of play ie if they all fit equal rubbish then customer has no where to hide thats my theory ,, i remember back in the 1990s when bmw and vag went to war over its diesel engines , vag had that 2.5tdi cambelt motor good engine came out of t4 as such they even shared it with volvo good motor and bmw had its 2,5tds 6 pot that well i had a few of them and could not kill them even after 230k still going strong,, so while they pushed each other to be better was all good built to last, then came the years of sharing engines and parts to save money so you end up with same faults crossing many brands, you also get the obsession with making cars light so reduces emissions ,, then there's the making a engine run as lean as possible without melting it down ie there is a point where a engine makes peak power to air and fuel 14.1 on petrol engines the only things that prevents it from lean outs is more fuel to cool the cylinder down,, but on these low friction tech engine with coatings this while engine is fairly new works ok and allows for a surplus of engine oil to help cool the combustion down,, so when they do the emissions and mpg etc it looks ike the engine dose really good mpg but reality is part pof the power gained is from low friction and oil allowed to apss and be used as fuel very slightly.. can you remember in F1 Ferrari got caught burning over 5 litres of oil by this process it ,meant that it could run less fuel technically reality was they could gain longer run time on 100kg of fuels and burning oil as well ,, also a bi-product is better controlled lean out so dont melt the motor down ,, its all about emissions and how fast out of warranty it will kill off the engine is my belief these days as its getting worse the newer stuff is getting to a point where its near impossible to repair half the time,, rebuilt a audi s1 a while ago thats standard 240bhp it was mapped out to 340bhp real weapon that had a injector go south after 50k and melt a hole through the piston and take out the valve seats in one cylinder ,,, the breaker wanted £4500 for the 20k engine he had and said he sells every one with in a week or two as common they do fail,, but for car owner things will get better when battery tech gets better as they just dont seem to have many parts to break ,, glad i'm at the age where i should see the last petrol and diesel cars go and that will be me retired
You have a good point here. The 2.5 TDI V6 that came after the cambelt one was also pure rubbish. I work at the main Mazda dealer and the diesels are just pure rubbish unfortunately...
 

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You have a good point here. The 2.5 TDI V6 that came after the cambelt one was also pure rubbish. I work at the main Mazda dealer and the diesels are just pure rubbish unfortunately...
mazda are using the older psa tech if my memory serves me right , and think some have the dpf filter mounted half way back the car and dont regen right over time if my memory serves me, bit like the new landrovers and the partial regens add unburnt fuel in to engine oil and destroys the engines for a past time from my past understanding of them ,, I get so peeed off with having to explain all this to customers and see their anger or hurt as they buy a fairly new car to find within 70k many times they have a 5k bill for engine job and new dpf filter etc,, and some look at you like its yours fault
 

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Discussion Starter · #13 ·
mazda are using the older psa tech if my memory serves me right , and think some have the dpf filter mounted half way back the car and dont regen right over time if my memory serves me, bit like the new landrovers and the partial regens add unburnt fuel in to engine oil and destroys the engines for a past time from my past understanding of them ,, I get so peeed off with having to explain all this to customers and see their anger or hurt as they buy a fairly new car to find within 70k many times they have a 5k bill for engine job and new dpf filter etc,, and some look at you like its yours fault
You really know stuff. Exactly. PSA tech was only the 1.6 diesel, which is basically the HDI engine.

The newer post 2013 2.2d are so problematic, turbo and camshaft faliures as early as 80kkm
 

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You really know stuff. Exactly. PSA tech was only the 1.6 diesel, which is basically the HDI engine.

The newer post 2013 2.2d are so problematic, turbo and camshaft faliures as early as 80kkm
i dont mind the 2,2 hdi psa engines they were shared with Mitsubishi outlander and Citroen c crosser and Peugeot 4007 even ford shared them with volvo as well , also out lander used a vag 2.0 tdi twin cam diesels as well as their own mevtec diesels that have a habbit of timing chain and cam shaft fails as well,
the 1.6hdi engine mini used it on r56 cooper d etc , its a better engine when remove the dpf and egr and also a must do is the gauze filter in the oil feed to turbo, they have a habit of injectors working loose and then cause hard carbon deposits that get past the rubber seals on the rocker cover and block that filter and cause turbo failure's that causes diesel runaway and destroys the motor, its all the EU car makers they share and also share the issues and add a few of there own a long the way, was time serves at a psa garage back in the day when 205 gti were the thing, even back then i was running golf gti with a turbo added to it, and even had a datsun 100A with a alfa sud 1.5ti engine in it twin ida down draft carbs thing would fly but not to good on non servo brakes lol,, steer it on right foot in the wet
 

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Discussion Starter · #15 ·
Okay, after quite an agressive drive the misfire seems to have got from happening a few times a month to constantly misfiring 3rd while warm.

Plugs, coils and injectors have been swapped by places and as I already thought there was no movement in the misfire.

As usual by disconnecting either the eccentric shaft sensor or either of the camshaft sensors, the misfire is gone as the valvetronic is locked to the fully open position.

Looks like it has started to drop a seat, or a valve seat is burned out.

Anyone has any idea?
 

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would pull the inlet and exhaust manifolds off, remove the rocker cover, set all 4 valves closed then can use a smoke tester is what i use these days putt smoke in to the plug hole under a pressure , if get smoke leaking at of a port then you know its that,,, will at this point look in to my crystal ball and tell you it will be exhaust valves and will be due to valve stem seals gone hard and oil has dripped down to valve and over time has lifted the valve off the seat ,,, they all go this way around 10 years old and 80-120k ,, head off job and clean and relap the valves pull sump and do the piston rings at same time fit better solid ones is the best cheapest fix,
 

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if dont have smoke machine use compressed air in plug hole while spray wd40 in the ports you are checking any bubbles that one is leaking,,
 

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Discussion Starter · #18 ·
if dont have smoke machine use compressed air in plug hole while spray wd40 in the ports you are checking any bubbles that one is leaking,,
Thanks for the reply.

All of this has been done a few months ago, including main and rod bearings, solid piston rings, head refurbed with new oil seals, seats lapped... really everything you can think of.

As a said, the misfire was there from day 1 after the rebuild, when it is driven pretty hard it used to misfire for a few minutes, and this would happen a few times a month.

An interesting thing that bimmerprofs are talking about in one article is that most valvetronic engine idle issues are caused by worn hydraulic lifters (mine also always made noise in the mornings).

The theory is that the intake valves lift at idle is about 0.4mm, if the lifters collapse even a tiny bit, the valve lift will be reduced, or the valves may not even open at all. This explains the engine working perfectly when you disconnect the excentric shaft sensor, because the system will apply maximum valve lift of about 9.9mm and the collapsed lifter will not do much at all now.

Valvetronic and HVA | Bimmerprofs.com | NOx emulator NOXEM 129 | 130 | 402 developed for BMW N43 & N53 series engines

This may be an interesting read for you.


I think I will replace the lifters for now and see what happens. They were really noisy in the mornings so they could very well be bad.
 

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failing all the above pull inlet manifold and exhaust manifold off and rocker cover , set all 4 valves closed on a cylinder and either use smoke tester in plug hole or can use compressed air and spray wd40 at each valve through the ports check for bubbles, if get any might of caught a valve perhaps , if spring fingers on vvt are not in correct groove will do the same trick, i have had them before where i put them back together and rotate a few times on bench then fit the head and on first start up one flicks out of groove this will cause misfires , also check all lifters are in correct, as its possible to drop the shorted exhaust ones in the inlet by mistake that causes all kinds of issues
 
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