Cause of concern?

[infamxkris]

hey guys almost about a year ago when i had my car at service for a service vehicle check and i was told by my SA that my car misfired cylinders 6 and 7. He told me that it misfired about 50 times during their "test". I was told that it was not something to be concerned with. At the time i took my SA's advice and left. Fast forward another year and i am starting to worry if this can be an issue later down the road. I am still under CPO warranty for i think about another year (does anybody know how to check when one's CPO warranty runs out?) and was wondering what you guys think i should do? Is this something bmw still would have records on if i brought it back or would they pretty much act clueless?

The car has 73,xxx miles on it and plan on keeping it for a long time after the CPO but i am growing really paranoid if the car will hold up. Ive created some threads over some time where i stated that the dct shifter on the center console kind of clicks when i am accelerating which i think happens when it is shifting gears, could this be directly tied to the misfires? It seems to happen alot more frequent than in the past. Any help or advice will be great appreciated. Help a fellow member that is STRESSING out!

[Koldun]

They will probably pretend they never heard of it, so I would ask for it to be documented. There was a guy on this forum who had similar issues that were ignored by his SA, until his engine finally blew a bearing in the middle of the road. At first, BMW gave him huge amount of hassle to the point that he had to get lawyers involved, but then out of "goodwill" ended up buying his car for a sizeable sum.

There are a lot of chicken littles when it comes to warranty claims, but I found if you make enough of a fuss, they will usually take care of stuff under goodwill even if you're clearly at fault. We had a former SA on these boards, telling stories about guys getting their engines replaced even after they literally never change the oil for 30-40k miles.

If you're planning on keeping the car, although I believe the concerns are way overblown (mainly by two particular individuals on this board who seem to really hate their car), it may be worth checking out. A lot of people have started to use much shorter oil change intervals, frequently get the oil analyzed, and some even prophylactically swap out the bearings when the warranty period draws to an end. maybe you should do the same, and use that as an excuse to get a supercharger? That is what I'm going to do.

In the end, try to not let it worry you too much. At least according to the admittedly anecdotal Consumer Reports, the M3 is BMW's most reliable car. This car is a solid beast by all other accounts, and you should be able to enjoy it for many years to come.

[happos2]

An engine just normally doesn't mis-fire all the time. Therefore, something is wrong and it should be fixed.

[infamxkris]

First i would like to thank you guys for the replies, I guess my question now is will they have this documented somewhere? Or is this going to be basically me convincing that they had actually told me that my engine was misfiring. The time they had told me he had a sheet of paper that had the information on it regarding the cylinders misfiring. But now I have no idea if they have it with my records or if it was just thrown out?

I am also currently under CPO warranty and was wondering if i had bring my car in would i be charged that diag fee of $150/hr?

Also any symptoms i should be experiencing regarding the misfires?

Also ive asked this numerous times without a straight answer so i will ask again in hopes of an answer, but the clunking in the rear is driving me nuts now i am 99% sure its the diff but every time i brought it in the past they always told me its normal for this car. Now this happens when i am coming to a stop and if i dont stop completely and accelerate kind of hard it feels like the diff in the back is about to just drop out of the car. This really does not feel normal to me and feel like its any day now that the diff will break off.

Sorry to sound like a broken record but this is really bothering me and has been for the past 3 years ive had the car, PLEASE HELP!!

[4corners]

Originally Posted by infamxkris

First i would like to thank you guys for the replies, I guess my question now is will they have this documented somewhere? Or is this going to be basically me convincing that they had actually told me that my engine was misfiring. The time they had told me he had a sheet of paper that had the information on it regarding the cylinders misfiring. But now I have no idea if they have it with my records or if it was just thrown out?

I am also currently under CPO warranty and was wondering if i had bring my car in would i be charged that diag fee of $150/hr?

Also any symptoms i should be experiencing regarding the misfires?

Also ive asked this numerous times without a straight answer so i will ask again in hopes of an answer, but the clunking in the rear is driving me nuts now i am 99% sure its the diff but every time i brought it in the past they always told me its normal for this car. Now this happens when i am coming to a stop and if i dont stop completely and accelerate kind of hard it feels like the diff in the back is about to just drop out of the car. This really does not feel normal to me and feel like its any day now that the diff will break off.

Sorry to sound like a broken record but this is really bothering me and has been for the past 3 years ive had the car, PLEASE HELP!!

you could replace the coils for the cylinders in question. And my diff is clunky in a glorious mechanical way. But check your diff bolts, especially the right side.

[baba louey]

I would think if the engine was misfiring 50 times over a relatively short period of time, the CPU would throw a code and the CEL or some light would show up on the dash. Most CPUs allow a few wayward engine (or any module for that matter) conditions before it decides that it's code time.

As for your diff, I have never felt that mine was going to drop onto the road. As stated above, check those mounting bolts.

[infamxkris]

Originally Posted by baba louey

I would think if the engine was misfiring 50 times over a relatively short period of time, the CPU would throw a code and the CEL or some light would show up on the dash. Most CPUs allow a few wayward engine (or any module for that matter) conditions before it decides that it's code time.

As for your diff, I have never felt that mine was going to drop onto the road. As stated above, check those mounting bolts.

Thats what i was thinking as well... In the time of ownership ive gotten the CEL light twice. Once it went to limp mode and the other time it happened when i was idle and it was idling very rough (vibrating alot), both times were fixed with a simple restart.

My thing is that if it does not go untreated will this be a huge problem later down the road? Granted i was told of this about a year ago and nothing has happened and nor would i have known if my SA hadnt told me.

If you guys were in my shoes how would you go about this? Would they still have this documented somewhere, where they can just look it up? Not really sure what type of action i should take from here.

[4corners]

Change the coils and plugs for 6 and 7.

[Koldun]

Regarding the differential, clunking noises during tight, low speed cornering is normal. There is a service bulletin where they can add a friction modifier if it bugs you. Some people argue that it's a bad idea, but lots of others have done it with no issues.

Clunking during deceleration/acceleration is usually a broken bolt. It's either one of the two bolts holding the exhaust bracket to the diff (these brackets can make a rattle when unsecured), or one of the three differential bolts themselves.

[happos2]

What fluid are you running in the diff? Also, when was it changed last?

[tdott]

Originally Posted by 4corners

Change the coils and plugs for 6 and 7.

or change all plugs and swap coils around to see if the misfires change cylinders.

Make sure you service your plugs fairly frequently as they are used to detect knock and are pretty sensitive.

Read this for more info, particularly the section about Combustion Quality: http://www.m3post.com/forums/showthread.php?t=919196

Originally Posted by THE TECH

The MSS60 does not have conventional methods of listening for ‘knock’ – rather, it uses feedback form the coils and plugs to detect combustion quality. The DME recognizes and records two main forms of misfires: ‘standard’ misfires, and misfires with combustion deterioration. The latter is a more severe form and will cause limp mode as such events can damage the catalytic converter and have a more pronounced effect on the engine.