Hi All,
I started having a problem with my Z4, the symptoms was on long fast runs at high revs when backing off i would occasionally get the engine management light on. This would throw up lean mix code in both banks 1 & 2. I would use carly to clear and and it would stay off for a month or two.
However before Christmas one day the car started up and struggled to idle, even in neutral the car when pressing the accelerator it would struggle to keep the revs, the car was responding if the throttle fly by wire system was not working properly, so i inspected the inlet hose and before people say check the inlet boot by the idle for a spilt, my M54 3.0i is different as its supercharged!! therefore the pipes are different.
Cut a long story short i replaces the MAF, ICV, DISA valve, oil breather hoses each side of the CCV, the oil ring on the dipstick, change spark plugs and coil packs. Took all hose off supercharger and check and refitted.
I then check car via DIS v57 and eventually no lean codes as i had a leak on the DISA O ring which i then replaced again, car still not idling!! so off with the ICV and throttle body to inspect, replaced accelerator pedal as this has a sensor in!. Whilst Throttle body was off i sanded down the inside to remove the lip either side of the valve. replaced ICV again this time with a Bosch part but still not joy.
Finally sorted the issue which was the aftermarket MAF units (2 of them) were this issue, replaced it with a genuine bmw part and all fine!!!
only issue with the MAF is mine is located behind bumper and headlight so they have been off many times in this episode!!!
Moral of the story is that genuine parts are expensive but in some cases are the right ones for the job.
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P0171 & P0174 codes
- mac27040
- Lifer
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P0171 & P0174 codes
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3.0i SMG Supercharged,19" CSL, AvinUSA android 10.25” screen,DSP,M6 gearknob,Coilovers,Aero F-bumper,M r-bumper,Aero skirts,Facelift front & rear lights,M sports seats,Carbon Steering wheel,Intravee,Rervese cam,Hydrographics
- Chris_D
- Lifer
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P0171 & P0174 codes
Blimey, you really took the long way round to find out it was the MAF eh!
But at least u can take consolation in the fact that u have replaced, cleaned or inspected parts that do actually fail eventually. Preventive maintenance is always better than remedial measures imo.
But at least u can take consolation in the fact that u have replaced, cleaned or inspected parts that do actually fail eventually. Preventive maintenance is always better than remedial measures imo.
E85 3.0i roadie (03) 'Benny'. E93 320d M-Sport Cabrio (11) 'Bob'.
'Always different, always the same.' John Peel on The Fall.
'Always different, always the same.' John Peel on The Fall.
- ph001
- Lifer
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P0171 & P0174 codes
Good read, and thanks for feeding back. MAF faults seem to be quite rare on the Z so I don't blame you for trying lots of other things first - then you had the issue of the aftermarket MAF not working. Must have been driving you nuts.
One question - did you ever try running the car with the MAF disconnected? IIRC the car will run reasonably well with it disconnected so this might have helped you home in on the problem.
One question - did you ever try running the car with the MAF disconnected? IIRC the car will run reasonably well with it disconnected so this might have helped you home in on the problem.
- mac27040
- Lifer
- Posts: 3511
- Joined: Wed Oct 26, 2011 5:17 pm
- Location: Shepshed
P0171 & P0174 codes
i did try at the beginning but as i had an air leak on the DISA valve it was still causing an issue and fail codes. This has driven me nuts, at least of have some sparesph001 wrote: ↑Mon Jan 14, 2019 3:16 pm Good read, and thanks for feeding back. MAF faults seem to be quite rare on the Z so I don't blame you for trying lots of other things first - then you had the issue of the aftermarket MAF not working. Must have been driving you nuts.
One question - did you ever try running the car with the MAF disconnected? IIRC the car will run reasonably well with it disconnected so this might have helped you home in on the problem.
3.0i SMG Supercharged,19" CSL, AvinUSA android 10.25” screen,DSP,M6 gearknob,Coilovers,Aero F-bumper,M r-bumper,Aero skirts,Facelift front & rear lights,M sports seats,Carbon Steering wheel,Intravee,Rervese cam,Hydrographics