I recently bought an 05 MCS with 6200 miles on it. 3 weeks after I bought it I was on the freeway and all of the sudden it was driving really rough and I looked down and the SES light and DSC light came on. I could not switch off the DSC. Upon restarting the car the DSC light went off and the SES stayed on. I took it to the dealer and they said the error came up as a misfire. They kept it 3 days and could find nothing wrong with it. They though it may be bad gas or a glitch in the computer. I only put 91 octane fuel in it.

I had it back less than a week and the exact same thing happened again. I made another appointment to bring it in.

Does anybody have any experience with this? I'd like to give them some ideas when I bring it back in since they found nothing last time. Any help would be much appreciated.

Thanks,
John

 

I can't say for sure what it is, but there is a ton of info in this forum about SES lights and intermittent misfires. I recommend that you do a lot of reading up on the info that's available. But I will tell you the following:

First, get yourself an OBD-II code reader. This will allow you to check the codes yourself, thus saving you a lot of time, frustration and possibly money at the dealship. If it's a occassional, single misfire that triggering your SES light it won't cause any damage to your engine and it will reset itself within a couple of days. But it's good insurance to make sure what code the ecu is showing.

Second, make absolutely sure that you use fuel that does not contain ethanol. BMW/MINI now has a service tool that they use to determine what % ethanol your gas is. If it's over 10% some dealerships will not cover related work under warranty b/c it will be deemed a fuel quality issue. This is exactly what the BMW/MINI tsb tells them to do. And keep a copy of every fuel receipt just in case things get out of hand.

Third, BMW/MINI has several tsb's that address drivability issues (including intermittent misfires). There are several links here on NAM that take you to alldata.com where you can read them for yourself. Some of the tsb's get into the problems with ethanol and others address the low level of detergents in most fuels. The tsb's recommend the use of "top tier fuel" or, where this fuel is not available, BMW's "Fuel System Cleaner Plus" every 3000 miles (costs $12/bottle).

 

Here's a link to get you started:

https://www.northamericanmotoring.co...t=49184&page=7