[spielnicht]

Just barely made it home at 10MPH. Car threw a Drivetrain Malfunction/CEL warning and performance slowly got worse and worse to the point where anything above 1K RPM would cause it to shudder and shake violently.

Got these 2 code from ISTA+:

• 118501 - Mixture Control 2: Fuel-air mixture too lean, large deviation
• 11A102 - High fuel pressure 2, plausability: Pressure too low

Just a couple of days ago I noticed a slight shudder when I was getting on the highway and did find 2 other codes (though didn't show up today):

• 190302 - Fuel tank ventilation system and purge air system, micro-leak: Leakage larger than...
• 193208 - Plausibility check failed between consumed and remaining fuel quantity

Engine is 100% stock - no engine performance upgrades ever performed/installed. I had the spark plugs replaced and engine tuneup performed last year by dealer (forced into it by BMW NA - long story).

There is plenty of fuel in the tank as well. ISTA+ Service Plan doesn't provide enough details on how to diagnose the codes.


Help!

[spielnicht]

Just got more interesting. Went back in with ISTA+ to see if I can pull more from the service plan and ended up finding new codes that had popped up.

From what I've gathered through scouring the forum and the net, multiple things can cause this and it's hard to pinpoint which. I really want to diagnose this and fix it myself, but have to admit I'm a noob when it comes to engine issues. I'll give it a couple more days to see if anyone here has any tips or I find something online before taking into the dealer to diagnose. At least if they give me the list of issues I can get the part and DYI-it then.

[Boosted M5]

Record freeze frame and clear the codes. Drive the car and see what codes reappear. It's obvious that it's only affecting bank 2 (driver side) and looks to me like it's a fueling issue.

[spielnicht]

Couldn't even get it for of the garage this AM - sounded like it was running on 1 cylinder and smell of fresh gasoline very noticeable.

Never had to tow any of my cars in the past until now, and I've owned a SAAB, Land Rover, Jaguar, and VOLVO. Never thought the BMW would be my first. Sigh.

Waiting to hear from the dealer.

[spielnicht]

Car is back and dealer was great to work with.

They found 2 problems:

1. Both high pressure fuel pumps were shot (putting out 2MPA vs standard 8MPA). Dealer replaced at no charge as they were covered by BMW. This was a $2500+ job, so that was A RELIEF considering I don't have a warranty.
2. 4 of the 8 coils were also shot, so they replaced all 8 and put in new spark plugs. This I had to cover myself, and it was costly, but considering the great service I got at the dealer and no charge for the fuel pumps, I'm OK with that.

Fingers crossed this the only big charge this year.

Also, tow truck destroyed my front lip - so I'm rethinking even resurfacing it or dumping it completely. Looked great - but def. not practical or convenient. Might just go M5 bumper option now.