Today’s car: G31, 530i with B48 engine; mileage around 60.000 km. The reason for the diagnostics:
a. preventive diagnostics (the car still has BMW/manufacturer warranty for the engine);
b. driving (especially in low RPM and high required torque), shivering can be felt (possibly – misfires).
It is planned to drive for long distances in the nearest future, so everything should be fine!
Fuel adaptations, oil pressure, fuel system – everything as it should be.
I have minor objections regarding the performance of the cylinders:
As we see, the performance of cylinder No.2 is 4. 6% larger than it should be, and it does not converge to 0. This problem should be checked repeatedly (true thou – after repairing basic things).
The performance of VANOS is correct – as for the new engine:
The image shows that both camshaft’s jitter is only around +/-1 degrees. I have to remark that the oil for this engine has been replaced after each 20.000 km (instead of 35.000 km typically). So: more frequent oil changes – zero problems!
An exciting nuance – in stationary conditions, DME regularly/continuously changes the required positions of the camshafts (as observed, it is not typical for B38 or B58). Accordingly – the camshaft (real/measured) position change, seen in the Call-UP functions, is not jitter! Here I have to remark: the camshaft’s required position can not be seen in the Call-UP functions, so the Expert mode should be used to evaluate the hubs’ performance.
Valvetronic works correctly:
In the image – a moment when VVT slowly makes a slight position change. Typically the position is maintained stable, and no problems, typical for B38, are observed.
Everything looks nice; no data available to the dealer (and with the equipment of the dealer level) indicate any problems. But, when making a test drive, the shivering of the engine can be clearly felt. Not so sharp as in the manual gearbox case, but subjectively – a regular misfire!
Here are the misfire counters in OBD Mode 6:
Yes, during previous driving sessions, there were more than enough misfires! Before reading the data, the car was turned off at least 2 times, which means: 2 units in the last 10 sessions – on average: at least 40 misfires during one driving session! A dramatic density of misfires. This is a massive load to the exhaust – CO catalytic converter and Lambda probes.
The first job to do – is to replace the spark plugs. Spark plugs (according to the owner, but – it later turned out that it does not correspond to the actual situation) are not replaced since the “birth” of the car. It turned out that new spark plugs were installed before 20.000 km. So – we have to find out the technical condition of them (yes, for these engines, if you are driving a “pensioner regime”, the spark plugs are “polluted” with carbon – they don’t clean, because the working temperature is too low).
Yes, BMW AG does not see the OBM Mode 6 counters (the use of OBD diagnostics tools is forbidden in the dealer service centers). To know the misfire counters, BMW AG service employees have to do a test drive with a connected iCOM; later – the data should be checked second by second. The lines should be drawn on the page of the paper. The reason is simple – for B series engines, in the EDIABAS system, “counters” are the event indicators, and cumulative data are unavailable. But this obstacle does not justify why the spark plugs are not replaced even by considerable mileage, even if the shivering of the engine can be felt.
P.S. Replacement of spark plugs solved all issues/symptoms.