The odometer of my own car has reached the border of 400.000 km. Over the last few years, I have diagnosed many B58 series engines. Most often, the symptoms and prognosis of other specialists (of different qualifications) have been harsh, as a minimum: damaged injectors, but there was also no shortage of supporters of the damaged engine version.
The scenario described below corresponds to at least 95% of problem cases, seen by me. Accordingly, there is a damn good chance that your car, too, will have exactly these problems.
Remark. This time I’m describing the car, which is in technical order, whose hardware and software are not “upgraded”. If the car is modified, it is logical that it may have (and typically there are) many problems – incorrect fuel mixture, most probably, even more serious problems. I am not a clairvoyant, and the problems of such cases must be seen in person. So, today’s scenario – the car drives as it has to, no error messages in the DME error message memory, everything is fine. And then suddenly IT happens.
Symptoms of the problems.
The vibration appears in the engine (can appear in idle, driving evenly, or in rapidly changing driving conditions). The maximal torque of the engine is reduced. The engine can suddenly behave strangely, as if someone were “holding” the accelerator pedal additionally. From the engine compartment, a beeping sound may be heard. Typically, the “Check Engine” sign lights up in KOMBI, in the NBT screen – notification regarding “Drivetrain malfunction”. From the exhaust of the car, a cloud of thick, white, and stinky exhaust gases is gushing.
Development of the situation.
There are several scenarios possible. In a small number of cases, the engine “repairs” itself. For a moment (around a minute), the engine behaves strangely, and the beeping sound can be heard from the engine compartment, but then the problems disappear. But in most cases, the problems are only progressing. In several minutes’ time, the vibration only grows, and the smoke becomes thicker. Typically, it all ends with a car parked on the side of the road and a call for a tow truck. If the engine is restarted directly after the problem is noticed (within several tens of seconds to one minute), typically the car starts to work correctly.
Prognosis.
If we check the advice of the “specialists” on the Internet (and their experience in the service centers), it is clear that the problems are serious. As a minimum, the PCV has to be replaced (more about PCV read here). The injectors have to be replaced. Spark plugs and ignition coils – yes, these are mentioned too, but for the “specialists” it is clear that so serious problems are caused by something more expensive. There is not even a shortage of those who are ready to immediately open the engine and perform its overhaul. I will remark immediately – I suggest not to listen to such “suggestions”.
Error messages in the DME error message memory.
First (during the first seconds of the problem), DME typically records the error message regarding an inappropriate amount of air:
101F01 Air Mass System, plausibility
Typically, as next, the error message regarding lean fuel mixture is recorded:
118001 Fuel-air mixture too lean.
During the next several seconds, DME identifies increased vibration of the engine and tries to identify the misfires. The error messages regarding misfires of some cylinders are recorded:
140X10 (X=1 .. 6) Combustion misfires, cylinder X detected.
After a moment, the “damaged” cylinder is already switched off:
140X01 (X=1 .. 6) Combustion misfires, cylinder X, cutt-off.
Very often, as a culprit, several cylinders are identified. Accordingly, after a short moment, the error message is recorded:
140010 Combustion misfires, several cylinders: detected
And then an integral part of the problem:
120408 Charging pressure control. Switch-off as a consequence.
The least popular are error messages regarding the Ignition period of some cylinder:
142 .. 150XXX Combustion period, Cylinder X, too short
142 .. 150XXX Combustion period Cylinder X, outside tolerance
After restarting the engine.
If the engine is restarted maximally fast (during the first minute), typically a normal performance is restored. During the first minutes, a pungent smoke continues to come from the exhaust (its amount gradually decreases till disappears).
If the engine is restarted later (allowing it to “struggle” for at least 2 .. 3 minutes), it is very possible that harsh shivering, misfires, and smoke will also continue after repeated restarting (more read here).
What next?
If the engine restores normal performance, it continues to work correctly till the next crash. When will it happen? Nobody knows. The next crash could happen now, in 5 minutes, or everything could be fine for the next few months.
If the engine continues to agonise even after restarting, you have several options. You can take your car to the service center. There, most probably, PCV; injectors will be replaced, or even the engine will be disassembled. Or – you can solve the problems on your own. How? Read further!
What will they do in the service center?
Service centres typically do whatever comes to mind. They will replace the spark plugs and ignition coils (true thou, I do not protest this because the spark plugs have to be replaced regularly, the ignition coils tend to overheat – they are not eternal either). They will replace the valve cover (PCV). They will replace the injectors. You can pay thousands of EUR for the repairs. In my experience, in NONE of the cases were the PCV or the injectors to blame. My conclusion – the possibility that the PCV or injectors are to blame, is very, very small! That’s why I do not recommend performing the replacement of these components if you are not 100% sure/it’s not approved that they are to blame.
What happened?
For the engine to crash like this, it is enough for one/several misfires on any of the cylinders. It’s the specifics of these engines. Why does the misfire happen in the cylinder? Most popular reasons:
a. due to an unoptimal fuel mixture. An unoptimal fuel mixture is the best friend of the “upgraded” engines. Due to this reason, don’t be surprised if your megapowerful/upgraded B58 “performs” like this time by time.
b. due to ignition system problems. There is no shortage of problems here – the spark plugs are clogging with carbon. The ignition coils are overheating (especially actual: idle, cylinders No. 5 and 6).
c. rare, but misfires can happen even for the engine in a perfect technical order. A microdebris can be in the fuel. In rapidly changing driving conditions, an imperfect fuel mixture can happen (yes, DME is powerful, uses intake-pipe and energetic module calculations, and still, failures happen even for such DME). If such a crash happens rarely and no connections between crashes (identical conditions/the same cylinders), it is possible – this is exactly the case.
Why are the consequences so catastrophic?
Misfires are the problem with petrol engines from the beginning. Why are B58 engines reacting so harshly to this long-known problem? The most important reasons for this engine:
a. problems with misfire detection. Siemens’ patent for misfire detection is still active. Bosch has to use methods of low efficiency. More read here:
b. Due to overheating, DME Ignition switches and ignition coils (and their plugs) for these engines, multi-ignition is not used (more read here). Accordingly, the spark plugs are not proactively dried. For this engine (due to unknown reasons), in idle, the engine compartment is not sufficiently cooled, as a result, the ignition coils of the last cylinders are overheating (they are additionally heated by the CO catalytic converter; read here);
c. due to misfires not identified in time, DME does not switch off the injector of the damaged cylinder, the Lambda probes are poisoned with the fuel, and it makes the correction of the fuel mixture impossible even when the misfires are finished. Not identifying misfires in time, DME “does not understand” what happened to the engine and damages a range of fuel adaptations, damaging the engine performance even after restarting;
d. DME recognises the misfiring cylinder very poorly (even if it suddenly “wakes up”, that the misfires are to blame), accordingly, very often it switches off another/correctly working cylinder, making the situation even worse. By identifying an incorrect cylinder as the culprit, DME starts to dry its spark plug (it can be heard as a beeping sound). Unfortunately, this drying does not help the culprit/damaged cylinder, which continues to inject the fuel into the exhaust.
Are misfires acceptable?
Yes, as already mentioned before, misfires can happen. From millions of ignition cycles, some can fail. For the correctly performing engine (the one that uses Siemens DME), there is multi-ignition. In unfavourable performance conditions, the spark plugs have additional drying. The engine compartment is cooled down in idle to prevent the ignition coils from overheating. DME identifies the misfire culprit very well – immediately (for a short moment) switches off the injector for the spark plug to dry, not to get “flooded”. No smoke in the exhaust. The Lambda probes are not poisoned. For such an engine, most probably, you will not notice such/separate misfire. If there is some ignition system damage, DME will record the error message correctly. But – this is not about Bosch and B58.
How to act?
a. if you notice the previously mentioned symptoms, IMMEDIATELY restart the engine. Immediately = during several tens of seconds. So you will avoid harsher consequences and complications;
b. if after restarting the engine restores normal performance, allow it to run in idle for some time (to clean the exhaust system). Observe the situation, later – check the DME error message list;
c. if the crash happened when in idle for a longer time, or in the error message list, the problems of cylinders No.5 and No.6 can be found (more often, exactly the 6th cylinder), replace the ignition coils of these cylinders;
d. perform the cleaning of the spark plugs from the carbon. Description read here;
e. if the engine shivers even after restarting, delete its adaptations (later – definitely perform the readaptation of the engine). Adapt the throttle. Restart the engine. If the engine starts to work on all cylinders, wait for a moment (for the exhaust to clear), readapt it. Observe the situation;
f. If, after deleting the adaptations and restarting the engine, it continues to vibrate, delete the error messages, restart the engine, and allow DME to record new error messages. Good news – during the first minute (after the start, during the warm-up of the CO catalytic converters) DME recognises the culprit of the misfires better (Bosch is cheating, bypassing the Siemens patent), accordingly, this time you can trust the error messages. Solve the problems with the damaged cylinder (replace its spark plug and ignition coil);
g. if such crashes tend to repeat more often, try to find the culprit (typically, a damaged ignition coil). Unfortunately, the checking of the ignition coils with advanced equipment (not even talking about the multimeter method, recommended on the Internet) typically does not give any result (more read here). If you feel some misfires in idle or on the go, you can use ISTA/Expert mode – here you will see the culprit.
