11th November: driving the car on damp / wet(ish) dual carriageway, sports mode ON, I give it some beans and it suddenly lights up like a Christmas tree, EML, DSC, DTC. Power lost instantly and within 10-15 seconds, the car is shaking and jerking horrendously, with RPM bouncing up and down between 1k-3k revs. Even at a stand still in park it shakes violently, so I switch the engine off. After maybe 1 minute parked up, I try to start it and it fires up fine with no issues and I drive it (gently) home OK. Although there are no lights on the dash at this point, I check the code reader once home and I have the following;
- 27C3 DME: Thermal oil-level sensor
- 2746 DME: Misfire, cylinder 2
- 281D DME: BSD generator : signal
- 28A2 DME: Air path:monitoring
- 5E19 CAN data fault from DME/DDE (DSC lamp on as long as error is present)
26th November roads slightly damp to dry, though it's cold and there's salt on the road. Weirdly the same stretch of dual carriageway, doing about 40mph and it changes to national speed limit, so I give it some beans with sport mode ON. Same issue as before and I nearly get rear ended by a van as I pull over. You have maximum 10 seconds or so before the car becomes undriveable. Turn it off, back on again and it's fine, just as before. Codes this time are fewer than previously, they are;
- 27C3 DME: Thermal oil-level sensor
- 28A2 DME: Air path:monitoring
- 5E19 CAN data fault from DME/DDE (DSC lamp on as long as error is present)
I know the second one (28A2 DME: Air path:monitoring) could be DISA related (plus the DISA was overdue a check anyway - thanks enuff_zed for the advice) so I pulled it out and had a look (short vid below) and all seems OK (though tomorrow I will take it out again, and just check the vacuum with the finger over the hole test).
https://youtube.com/shorts/bEr-pupjRX4? ... mGzKowuvs3
Other forum posts (not necessarily Z4's but still the same M54 engine) have suggested anything from intake leaks, DISA problems to MAF sensor issues for this (28A2 DME: Air path:monitoring) issue. I even found this random BMW service bulletin (link) recommending changing the mass air flow sensor and NOT the DME.
For the 5E19 CAN data fault from DME/DDE code, I found a thread on Bimmerpost for an E92 that is the EXACT same faults / dash lights / violent limp mode (link here) and the fix was replacing and coding the DME
I'd be enormously grateful for advice / thoughts as it's pretty scary when it happens. I wouldn't want to be in lane 3/4 on a busy motorway with no hard shoulder with this fault because you have just seconds before the car comes to a halt.
Do I get a mechanic to smoke test the intake system, double and triple check the DISA and go from there, or am I wasting my time and should I just bite the bullet with the DME / coding for it? Is it OK to buy used ones of these? My current DME is part number 12147532140. There are no leaks / visible damage to where it's sited.
I've only owned this car 18 months and have already sunk a lot of money into it (I'm scared to total it up but probably close to £3k now), but we (myself and the Mrs) have some things coming up in 2024 that are going to be expensive, and I really don't have the spare cash to be sinking a load more money into it in the short term. If it's going to be seriously expensive, I'd probably just park it up and SORN it until April, which will (hopefully) be bonus time at work.
Any help / advice from this wonderful forum (a shout out to enuff_zed and wassup particularly!) would be much appreciated.
Cheers, Ross