I have a 2010 mini cooper base 1.6 that misfires when warm and runs perfect when cold. I have misfire codes and oxygen sensor code. The cylinder that has a noticeable misfire is cyl 3. I have tried moving coil, injector, and spark plug to a different cylinder and misfire stays in cyl 3. I have checked compression and all cylinders are good. I have also checked fuel pressure and it is good and stable when cold and warm. I have seafoamed and issue remains the same. I have noticed that when misfire begins when warm if I disconnect either cam sensor or either vanos solenoid the misfire stops and idles smooth again. Any one have any ideas on what it can be?

 

Hi
I'm having the opossitive issue in my 2010 Base 1.6.
Misfires when COLD and all normal when hot.
In my case the fail points to the fuel pump on the gas tank.

But I have not error codes stored on my car.

Can you tell me please how do you get the cylinder compression and fuel pressure cold/warm info from the car?

I'm a INPA and ISTA Rheingold user.

Thank you so much.
I hope somebody with the knockwledge here can help you with your car behaviour.

 

Answered you over at your other thread: https://www.northamericanmotoring.co...d-problem.html

 

I checked them with gauges when cold and when hot

 

You could have a mechanical timing issue, or VANOS solenoid problem (not all cases can be fixed by cleaning the solenoid, it seems that every other car in for a VANOS solenoid problem needs it to be replaced).

I had a car earlier this year that had a corruption in the DME for cylinder 3, causing a limp spark in cylinder 3 which caused a misfire.

You need to find a shop with a quality scan tool to monitor VANOS requested vs actual readings.

 

Any other way to test it?

 

Nope, you need a scan tool that will read VANOS actual vs requested, as well as timing tools if you want to check static timing.

 

What was the fix for the vehicle?? - I'm having the exact same issue...car starts and idles fine once you drive around for about 20mins and/or the engine gets to normal operating temp the vehicle will misfire from cylinder #1 - I've swapped the injector(misfire doesn't move) replaced coils+spark plugs (OEM Mini) - checked fuel pressure at rail with gauge reading 50psi - removed/cleaned and swapped VANOS solenoids, oil level is correct - performed compression test - test shows good compression.. anytime the vehicle misfires it will continue to misfire from cylinder one until I disconnect either camshaft position sensor - then the engine hiccups then will run without misfire. I'm viewing this with ista/d BMW Software... any ideas??

 

https://www.northamericanmotoring.co...d-problem.html

 

wish mine where as easy as that - I've removed my VANOS, they are the updated units and they were clean and sludge free - I watch my VANOS commands and set points and every thing lines up..... anyone else have a suggestion?

 

Eurotech 1. I am having a similar issue on my 2007 N12 engine. Did you find a fix?

 

 

Has anyone found were the problems was?

 

Did you find a fix?

 

Did you find a fix?

 

More for the benefit of people looking for an answer to their hot idle misfire problem. If you have an n12 engine that is suffering from a hot idle misfire, it is likely that you have a loose inlet valve seat on the cylinder that is misfiring. Why the n12 presents the misfire while the n14 doesn't is because of the VVT technology. In the case of the n14 a loose valve seat results in an eventual destroyed engine while the n12 gives you a warning through a misfire at idle but if you fail to resolve it, the engine will eventually be destroyed. Through VVT the inlet valves lift at idle is very shallow and this results in the valve with the loose seat not sealing and loss of compression - resulting in a misfire. When you remove a cam sensor the VVT is disabled and the valves move to full lift at idle and the misfire stops. So if you have a R56 that is misfiring at idle when hot, try disconnecting a cam sensor and if the misfire stops, chances are you have a loose inlet valve seat. A lot of engine specialists are aware of valve seat issues with the R56 however too few people have tagged the loose valve seat issue with the hot idle misfire. My partner has a justa that had the hot idle issue which we were able to fix, without using the parts cannon! We engaged the services of an engine specialist after a mini specialist demonstrated a total lack of understanding. By replacing a loose valve seat the justa no longer misfires. At the same time I stopped the dreaded oil consumption that plagues the R56 engines through replacing valve guide seals and scraper rings, went from 1 litre per 800 miles to no oil consumption on a 125,000 engine. We will keep the car for a couple more years and then sell on, but will not return to either the BMW or Mini brand. Gen2 engines are a disgrace and BMWs behaviour is appalling with not addressing the many issues caused by putting into production an engine that was not production ready.

 

More for the benefit of people looking for an answer to their hot idle misfire problem. If you have an n12 engine that is suffering from a hot idle misfire, it is likely that you have a loose inlet valve seat on the cylinder that is misfiring. Why the n12 presents the misfire while the n14 doesn't is because of the VVT technology. In the case of the n14 a loose valve seat results in an eventual destroyed engine while the n12 gives you a warning through a misfire at idle but if you fail to resolve it, the engine will eventually be destroyed. Through VVT the inlet valves lift at idle is very shallow and this results in the valve with the loose seat not sealing and loss of compression - resulting in a misfire. When you remove a cam sensor the VVT is disabled and the valves move to full lift at idle and the misfire stops. So if you have a R56 that is misfiring at idle when hot, try disconnecting a cam sensor and if the misfire stops, chances are you have a loose inlet valve seat. A lot of engine specialists are aware of valve seat issues with the R56 however too few people have tagged the loose valve seat issue with the hot idle misfire. My partner has a justa that had the hot idle issue which we were able to fix, without using the parts cannon! We engaged the services of an engine specialist after a mini specialist demonstrated a total lack of understanding. By replacing a loose valve seat the justa no longer misfires. At the same time I stopped the dreaded oil consumption that plagues the R56 engines through replacing valve guide seals and scraper rings, went from 1 litre per 800 miles to no oil consumption on a 125,000 engine. We will keep the car for a couple more years and then sell on, but will not return to either the BMW or Mini brand. Gen2 engines are a disgrace and BMWs behaviour is appalling with not addressing the many issues caused by putting into production an engine that was not production ready.