Another thumbs up for an OBDII to do your own simple check. They are not a full get out of jail option but are useful. I have an Autel Maxiscan bought to use on my Rover V8 car. It helped for two situations of EML light coming on. Faults identified were
1. Random Intermittent Misfire. Solved by using higher octane petrol after checks on plugs, leads, other connections etc.
2. Downstream oxygen sensor heater circuit fault [ post cat).
Both solved fairly easily.
The Maxiscan also lets you do engine running monitoring where you can see a lot of useful data. It helped me ID which one of two sensors was faulty by looking at the voltage readouts from each one.
As for the Vanos on the BMW it reminds me of the Honda Vtec system of ( if I remember correctly) oil pressure opening a valve to trigger a timing change at higher revs. The cure was usually a new valve trigger unit not a big head rebuild.
Having just moved to a Plus Four with a BMW engine I have entered a whole new world!
It’s amazing that in modern engines so many things link to the ecu to trigger an EML light. Most are ok as they can prevent problems but some seem OTT. Nice tip about sump dents though. The speed bumps in my area are breeding fast and many must be out of spec for shape/height seeing how even the Kia reacts to them.
