Hello, I have a 2010 mini clubman non-s model.... it's the N12 engine.. I have a cylinder #1 misfire that won't go away... 4-new mini dealer spark plugs... 4-new mini dealer spark plug coils.... I'm getting misfire counts on cylinder #1 at idle when warm..... I've verified I have good fuel delivery at rail pressure checked with gauge... also verified it's not the injector.... when the cars up to normal operating temp it starts misfiring.... I feel I rev the engine up to above 3k holding idle there, the misfire goes away.... at idle when misfiring if I pull a cam sensor electrical from sensor the car hiccups and then runs normal again... vanos seloniods removed inspected tested at 7.3ohms and swapped locations, they didn't look dirty or clogged in any way... any advice on where to go from here? Thanks

 

You did pretty much all tge basics. I suggest a compression test to confirm a healthy cylinder.

 

Already performed compression test warm cylinder #1 equaled 168psi... the other cylinders are within 10psi.... no other fault codes except cylinder misfire #1 and random cylinder misfire..... when it starts misfiring when warm, if I disconnect a cam sensor or vanos sensor the engine hiccups and starts running normal and the misfire goes away.... any ideas?

 

how did the misfire happen...what is the back story so we can identify the events leading to the issue.

you mention if you remove the cam sensor, the misfire goes away. clean/replace that sensor and see if the misfire goes away for good.

 

I just bought it so I don't know any back story with it... I've already cleaned the cam sensors made sure there's no wiring issues.... I noticed if I pull the exhaust vanos selonoid electrical connector with the car running it hiccups then starts running without misfiring (same thing as pulling cam sensor wire).. I believe by disconnecting any one of those electrical connections it puts the car in a "base timing mode" which I believe disables VANOS and Valvetronic.... as soon as I plug back in and cycle key on then start engine, the misfire will return to cyl #1.....until I rev the engine up to 3k... anyone have this issue?

 

the vanos could be bad despite the cleaning

 

Thank you for at least replying to my post, I've seen a lot of posts similar to mine but they go unanswered or the original poster doesn't post back with what resolved the problem..... I'm not showing any other faults except the misfire cylinder one and a multiple cylinder misfire as read on BMW diag tool, if you read with generic scanner it just shows cylinder 1 misfire code.... I've watched misfire counts and I'll see occasionally a misfire from another cylinder of less than 3counts but they go away, cylinder one misfire counts go up 150+ and continues misfiring the misfire can clearly be felt... any other ideas? I haven't checked base chain timing yet, possibably off time? Stretched chain? Bad tensioner? Any other ideas?

 

no problem my friend. i like helping and i like it even better when we fix it.

when you start the car, you feel the engine slightly shaking, right. if you unplug coil one, does it change or it remains the same?

since the cams are all tied to the same chain, if you have a bad chain, let's say, then the misfire will be on multiple cylinders not just one!

knowing the back story of the car can lead to the solution.

 

No vanos codes?

https://www.northamericanmotoring.co...nos-fault.html

https://www.northamericanmotoring.co...solenoids.html

 

Thank you both for the replies... I have ista/d and performed valvetronic relearn, I've performed VANOS system check... and all my readings are within the specs given... I've pulled both VANOS solenoids, they look relatively new, definitely the newer design without the windows. Looking at misfire counts I get blips once in a great while from other cylinders but cylinder #1 is definitely the problem cylinder with continuous counts. I don't have any fault codes except "cylinder 1 misfire" and "multiple cylinder misfire" when scanned with ista/d, the only other code I have ever pulled on it besides the misfires... was a "o2 sensor monitoring before cat" but I guess that codes being thrown because the severe misfire from cylinder #1 causing bad o2 readings so I've ignored that fault which I've only pulled twice now..... I've performed a dry compression test when warm on cylinder #1 read 167psi from what I remember (have it written down but not on me) I bought the car a couple weeks ago with the check engine light on from a friend who bought it from an auction. So I have no history on the car... any other ideas? I've pulled valve cover off and inspected, nothing looks wrong with the visual of the internal cylinder head... any other ideas?

 

If components are good an mechanics are good, the only two things left are the engine wiring and the ECU.

I bought a car from the auction with a deep front end collusion. After fixing and swapping parts, the check engine was "stuck" with a MAP sensor code despite me changing the sensor three times. The plug was broken and the wires touching. At the end, i got another ECU cloned and the check engine light went away.

Just a thought!

 

What do you mean the plug was broken and wires touching, so you replaced the DME?.... could I get another DME and swap it in to test? Or does it have to be coded to the car? I wouldn't know why else I'd have a misfire, I verified spark... I tested fuel injector function with a noid light (after about a miniute with the car running and the noid light flashing from the connector, the light would stop... I'm guessing the dme senses the injector not firing and turns off) I've verified fuel pressure at the rail, and compression... any ways I can test the DME?

 

The plug was smashed from the accident. I bought another matching DME and had a guy clone it for me from ebay.

A DME swap wont work unless you send it for cloning from your original.

Did you verify gas coming out of the injector?

 

I'll take a good look at the wiring and connector at the DME tomorrow. I swapped injectors so that eliminated issue with injector, plus the car will run fine once one of the sensor connectors is pulled off remember..... again why does it run normal when a connector is pulled out?

 

My only theory is interference between these two sensors which leads to wiring. Right? Was the car in an accident or fire or something else