strange issue

lmcconnell · 11th August 2012, 07:13

I've posted this elsewhere online, figured I would try here. I have an 06 E60 M5.. I am experiencing an odd issue. Anytime I have to get gas, if i put gas in my car..pull out of the gas station and get stopped within roughly 5 miles.. my car's idle goes a bit haywire. It will start dipping up and down, and then eventually (if i dont do anything) I end up with the dreaded "Engine malfunction - Reduced to half power". The odd thing is if I don't stop within a few miles..it goes away and then I don't have any issues at all again until the next time I get gas. I can shut it off, drive it, park it. etc.. no problems at all until time comes around to get gas. I have had vanos replacement, have tested coil packs, ionic module, fuel pressure test. Still no answers. Anyone else encounter this?

Hasan Shaikh · 11th August 2012, 09:15

It seems you have a problem with your fuel system.

I would suggest you get the car checked professionally.

bayerischemotor · 11th August 2012, 09:18

Do you leave the car running when filling up? Just thought if there could be air developing in the fuel line. Long shot.

lmcconnell · 11th August 2012, 18:19

Hasan: The very first thing I did was take it to the dealership. It's actually been to two different dealerships in hopes of fixing it ( hence vanos replacement, coil packs tested, ionic module tested... etc.) They can't find the solution. I think in part because they misunderstand the issue.

bayer: nope, never get gas with it running.

It seems when it happens, the entire left bank will misfire. (moved coil packs, etc the misfire did NOT follow) and its only temporary after getting gas.

Gavin S. · 11th August 2012, 18:57

I have an 06 and it exhibits this same behavior. Wonky idle a few miles after fill-up. I just figured it had to do with the pressure being lost and rebuilding in my gas tank, but I did get my first engine malf-reduced power light the other day. I turned off the car and restarted right away and the light was gone. Has not returned. I can't remember if it was withing a few miles of refilling, though. I have an appt to get the codes pulled this Wednesday.

lmcconnell · 12th August 2012, 22:04

well good luck when they pull the codes. If you happen to hear something, please let me know!

I've called a couple independent repairs shops at this point to just kind of pick their brain a bit to see if anyone else has come across this. Will post back anything I find out eventually.

Skills · 16th August 2012, 15:52

Quote:

Originally Posted by lmcconnell

well good luck when they pull the codes. If you happen to hear something, please let me know!

I've called a couple independent repairs shops at this point to just kind of pick their brain a bit to see if anyone else has come across this. Will post back anything I find out eventually.

Did you take your beat to the dealer? What did they say?

Gavin S. · 16th August 2012, 17:52

Quote:

Originally Posted by lmcconnell

well good luck when they pull the codes. If you happen to hear something, please let me know!

I've called a couple independent repairs shops at this point to just kind of pick their brain a bit to see if anyone else has come across this. Will post back anything I find out eventually.

They pulled the code on my car and it came back as cat convertor efficiency fault banks 1&2. Not currently present and all systems working to spec. Hopefully it was an anomaly and nothing comes back but I'm not counting on it. At least I got my dreaded fire-starting battery cable replaced.

Orion21 · 16th August 2012, 18:23

I'm no expert and don't even know the name of the part, but:

Guys have had issues with the part that is responsible for maintaining pressure in the fuel lines. It may be that this part is failing and it is taking it sometime to re-pressurize properly, hence the wonky idle. Just a theory...

tbrown1985 · 16th August 2012, 19:07

I had the same issue for about 8 mos. Crazy idle after filling up. Never any codes, just bad idle and would die after getting gas if I did not begin driving immediately. Got used to making sure I had plenty of room before pulling on to the street, because it would always bog down on the first press of the throttle. Stopped doing this about 6 mos ago, and has been fine ever since. Go figure.