The owner of quite a rare and interesting car approached me. The car: Alpina B5, E61 body.
The car is not used during wintertime, accordingly – the owner wanted to know, what should be done for the car to welcome the new driving season in “top zustand” condition.
My task: observe the general situation, paying more attention to the engine.
There are many assumptions in this entry because of only the initial stage: problem identification – of the diagnostics is performed. Causes and solutions should be still found out. But such entry, in my opinion, is even more interesting because I describe several scenarios, not in short – incorrect value of live data / replaced spare part / everything is fine.
Short info. Alpina built this car based on the V8 N62 engine, supplementing it with the compressor. After upgrade, the engine reaches 500hp and remarkable 700(!)Nm.
It seems, that Alpina has not especially rebuilt the engine management, limited only with a change of the management maps. The compressor perfectly fits for the upgrade of the engine – the air flow-rate and pressure is predictable and additional rebuilt of the engine management is not necessary.
Here, even the key with Alpina logotype
And KOMBI in a habitual Alpina blue
On the steering wheel – places to add the booster, if the electricity disappears (joke).
Why do I mention booster and electricity? The battery problems I will review first hand.
The equipment of the car – abundant enough. Alpina did not rebuild the car with a mechanical window lifts!
As you see, part of the modules – with error messages
The error message list – at least one half (for example, the disappearance of LIN data bus) could be related to the problems of the power supply – voltage problems. Of course, it has to be checked more in details but at first – the Undervoltage problems should be solved.
Here, the error message regarding the error of battery voltage data package, Undervoltage notices were regular.
At this moment I opened INPA to see the situation of the IBS system.
As you see: around 20’000km ago, a new battery was registered. Is it damaged?
But SOH is negative!
My experience says – negative SOH is calculated if the time aging component is very large. It means: the car believes, that the battery is very, very old (it is used for many thousands of the motor-hours). But at the same time – as if relatively recently the new battery was registered! How so?
Here, the data of the energetical balance.
It looks that the IBS system has desperately tried to charge the battery (its ”charge – discharge” = not 5 .. 7%, as in a correct situation, but significantly larger), but – without success.
How could such a situation appear?
I have said many times – register the battery, only using ISTA D/+. Do not use INPA. Do not use 3-rd side tools (Lauch, Alphi, PioTools etc.). All these 3-rd side tools use INPA scripts. INPA, in turn, fails! The change of the battery (the event itself) as if it is registered, but the energy, SOC and SOH registers are not cleaned/initialized properly and correctly.
What are the consequences? The battery stays in a partly-charged state, the sulfuric acid corrodes the lead plates. And of course, as the largest part of the battery is not used – when colder weather comes, the clock of the car starts to “disappear”, finally – the problems with starting the car appear.
In this case – unfortunately, the battery should be replaced and registered CORRECTLY.
Now let’s focus on the performance of the engine.
As you see, there are error messages for misfires of at least 3 cylinders. In addition to the indicated cylinders, there is an error message “misfire of several cylinders”, which means – the total amount of the misfires is significant. So – the problems with the fuel ignition (large problems, because as we know, the Bosch DME registers misfires very reluctantly). They can be caused by defects of spark plugs and ignition coils, also by incorrect fuel mixture.
First thing, which I check: mechanical efficiency of cylinders. It shows the “health” of cylinders.
The data are not perfect. DME has not succeeded in even the performance of the cylinders. Here, for example, cylinders No.2 and No.8 are for 10% more efficient than the average value, No.4 – for approximately 10% less efficient than the average value. Unfortunately, such (not smaller) differences from an ideal situation remain for all time of the diagnostics, also when the engine was warming up and when it was already warm, it means: DME does not fix the situation even in a long time. In addition, such a high difference from ideal is in “relaxed” conditions (with partially turned-off Valvetronic – the description will follow) – the situation is far from perfect.
This engine still uses regular electro-magnetic injectors, their parameter dispersion is small. The injectors will not be the cause of this situation. The typical cause of such problems is a different amount of air in cylinders. This problem appears due to Valvetronic – the elevation of the inlet valves does not correspond to the required. This problem, instead, appears due to defects of inlet HVA, which are deepened by the problems of oiling.
The version of possible problems with HVA is deepened by the obstacle, that the error messages are registered for cylinders No.1, No.4 and No.5, which are relatively “weak” (especially No.4 and No.5). Weaker – so with the lack of air. Possibly, there are obstacles (for example, idle after higher load, when the oil is heated close to the max temperature), in which the disbalance of cylinders is larger than observed +/- 10 .. 15%.
The problem must be looked at deeper. Of course, it has to be started with inspection/evaluation of the spark plugs and, if necessary, replacement of them. The density of misfires has to be evaluated after the replacement of spark plugs, using ELM. Damaged ignition coils should be replaced.
Now I did not check the data of misfire density, because they have to be checked after the initial repair. With weared-out spark plugs, the results (and, accordingly, conclusions) will be incorrect.
Note. The dealer does not see the misfire counters. Accordingly – in case of uneven performance of the engine (misfires) the dealer is helpless. Yes, all spark plugs and ignition coils can be replaced, but – will it solve the problem? Which cylinder continues to misfire? The dealer can not indicate it, because such data are displayed neither in ISTA D/+, nor INPA (true thou, the dealer is not allowed to use even INPA).
After revision of the spark plugs and ignition coils, the engine has to be readapted and – if the efficiency of cylinders is not in range of +/-5%: the problems with oil pressure and inlet HVA should be solved.
One more problem: the value of the Lambda of the second bank. When the engine warms up, Lambda of the 1-st bank was 0.98 (in this stage, slightly enriched fuel mixture warms up CO catalytic converters), but in the second bank 0.95 .. 0.96! Such value is incorrect, but DME does not even try to solve it. When the engine warmed up, 1-st bank switches to the Stoichiometric mixture (it is correct), but the second bank stayed by 0.97 .. 0.98.
Here, INPA also confirms that the wideband value of the 2-nd bank does not reach to 1.500V (after trimming), but are “stuck” by strongly decreased value. Compare – Lambda value of the 1-st bank: 1.498V, which only for 0.002V differs from the theoretical ideal.
Such Lambda value means rich fuel. These several (as if small amount) % of left-over fuel continue to burn in the exhaust pipe and significantly overload the CO catalytic converter. If such problems are not solved immediately, the CO catalytic converter is damaged!
There is no doubt – for some reason, the engine works in emergency mode. Unfortunately, not ISTA not INPA, does not display Integrators, accordingly – to solve the problem, specific tools should be used (external AFR measuring tool) and oscilloscope (to evaluate the reference value of the wideband probe).
In the beginning – of course, the engine should be re-adapted, which, as it seems, was not been done for a very long time. Obviously, the car was serviced in the service center, which has not heard anything about the re-adapting of the engine.
In conjunction with this problem – it has to be checked, how (after readapting) the DME trims the wideband probes, and do the indications of the control probes reach target values.
One more value, which looks more than suspicious: performance of Valvetronic. The lift of the inlet valves is around 0.80mm, which is at least two times more than typical for the N62 engine. So – the engine uses Valvetronic only partially. There could be several reasons: an increased difference in the mechanical efficiency of cylinders (it should be solved at first hand), problems with limp mode (value of the Lambda of 2-nd bank). DME uses increased valve lift to reduce differences in the mechanical efficiency of cylinders – by the larger movement of the valve, the impact of HVA problems is reduced. It is important to remember when evaluating the differences from the ideal of cylinder performance. Or, maybe, someone increased minimal lift of intake valves manually to reduce (”solve”) problems with uneven idle.
And finally: DME has noticed problems with the heated thermostat. How we understand from the freeze-frame of the error message
The data of incoming coolant even for the warmed-up engine is incorrectly low. Accordingly – either the temperature sensor itself lies, or the thermostat and/or its heating works incorrectly. This also is a critical problem, because it can limit the power of the engine and paralyze the creation of the adaptations.
During diagnostics, I also checked the adaptation data of the gearbox. Pressure adaptations are not created for the last two (C and D) friction discs. There could be several reasons – engine problems, problems of the gearbox itself (conditions to adapt these segments are not reached; results of the adaptations are very variable and for this reason, they are deleted/cleared). In any case, additional attention should be paid for it. A little strange, that in the previous time, when the gearbox was adapted, these problems were not solved.
The situation with VANOS, Valvetronic itself, burning of the fuel (detonation data) is correct, so I did not go into these topics. The performance of the compressor, instead, can be evaluated only on the go.
In kickdown mode:
- it has to be evaluated if the fuel mixture does not get too rich (Lambda below 0.85 .. 0.90);
- in the segments of the full required throttle multiplicative type LTFT adaptations did not get relatively significantly negative (against the segments of lower RPM).
Both symptoms indicate a lack of air, which can appear due to the insufficient performance of the compressor. Instead, if the adaptations are in the allowed range (the corridor), slightly reduced performance of the compressor will reduce max torque, but the fuel mixture will stay correct and the error messages regarding it will not be recorded.
Also, Offset type LTFT are correct, for now, there is no reason to worry regarding the air-tightness of the inlet manifold.
Finally – maybe will be of use for someone.
Here, the CBS data of the car
As you see, the oil has been changed 16 times. According to CBS user data or checking the mileage left to the oil change, the oil change interval can be indicated. It is possible to evaluate the possible mileage of the car, knowing the number of oil changes and oil change intervals.
Possible mileage, because – it can happen, that irresponsible car owner has been regularly driving with a warning message in KOMBI. It can happen, that CBS data are deleted by incomplete intervals. For F series – it can happen, that CAN filter has been installed. But, these data suit for insight – roughly modified odometer data can be seen very well.