In this entry – how important is choosing of proper servicing place. How important to make a pre-buy diagnostics.
I have no right to reveal the name of the exact service, and it is not decisive, because the situation, unfortunately, is not unique. Probably, this is the toughest case that I have seen before, but – not the only one.
A previously unknown service center asked me to help, their story was – “the customer came. Everything was fine, then he filled the fuel tank, the engine suddenly lost power, the engine started to vibrate – something broke down. Now it is even hard to start the car. Already two specialists have checked the car, the verdict of both was – damaged DME”.
I have to add immediately – there is a lot of lie in this story. But about them – a little later.
I will not bother you with any images, because the aim of this entry is not diagnostics, but – to understand, how the rustle of unqualified personnel can result (actually – for the customer this story only starts).
But let’s go back to the car. A BMW E82 with N43 engine, the manufactury year 2010, expects me. Connecting INPA, I detect, that there are several tenths (!) of active error messages regarding many hubs: crankshaft sensor, oil pressure, Lambda probes, real/required torque, etc.
Checking live data, immediately following abnormalities are present:
- there really are no data of the crankshaft sensor;
- there are no data of low-pressure fuel system (indications stuck around 6000 hPa);
- HPFP runs in an emergency mode with fixed pressure around 150 Bar (regardless of RPM);
- Nernst resistance of the wide-band probe(s) is (are) incorrect, there is no chemical activity;
- contamination of the NOx catalytic converter is 1 mg, it is clear – the NOx system does not work for a long time already (it is damaged);
- The offset of the NOx sensor – incorrect, Online mode is not reached;
- adaptations – unfinished, but the learnbits and test data indicate – the engine has not been re-adapted for a long time (it means, there is no correct maintenance performed);
- chemical efficiency tests of cylinders indicate flowrate problems in cylinders No.3 and 4;
- live data indicate the flowrate of the injector of cylinder No.4 is out of the allowed corridor;
- last time, when the engine has run in Stratified charge in idle, the injector of cylinder No.4 was leaking; in the mode of partial load – problems for several injectors;
- Offset type LTFT values of both banks are incorrect – the inlet manifold is not airtight;
- DME runs in an emergency mode – LTFT of both banks are averaged, individual adaptations of the injectors – not applied.
At this moment it becomes clear, that I’ve been lied to. Stories “everything was perfect” are false, because the engine simply was not able to function normally with such problems. But the service specialist continues with the same story. True thou, now some facts are added to the story: the crankshaft sensor has been replaced, but without success (the error message regarding its indications appears repeatedly). HPFP has been replaced (of course, a second-hand spare part with unknown mileage has been used). To the question, what was the reason to replace the HPFP, the consistent answer does not follow.
”The sensor of the Rail pressure was replaced because the pressure was lowered. It didn’t help”. What should be the Rail pressure – obviously, the “specialists” have no clue.
When I mention VANOS, DISA, NOx, Stratified charge, the master startles the eyebrows in amazement and asks “what is that?”… Unfortunately, I have no illusions regarding the qualifications of the specialists in this service center.
But what could happen to the engine? Why it does not “sees” the crankshaft sensor? Why so many systems have broken down?
When I mention to the master, that there are many problems, which need to be solved, he outragedly cries “you want to tell me, that a lot of money has to be invested in this car? The car is sold already! It has to run! Without extra investments!”
He offered to try a used injector from a neighboring car dump. At that moment I understood I do not want to cooperate with such “specialists” and left. But the sentence “the car is already sold” sounded interesting.
But there still is an intrigue – what is the history of this car?
This intrigue was dispelled by the owner of the service, who (later, in a phone conversation) admitted, that the engine of the car was replaced. What has happened with the previous engine – unknown (it also does not matter, because it is clear, that the “specialists” of this service do not understand almost anything of these engines). Now it becomes clear, that the cause of the many problems is unqualified repair, not “everything was fine, and then the customer refilled the fuel”. Obviously, the service has bought the car with an engine problem, and now it has been “repaired” by this service and successfully sold to the customer.
The simplest explanation of the crankshaft sensor problem: connectors of the crankshaft and LPFP pressure sensors are mixed with places. It would explain also the missing indications of LTFT. Of course, DME has no problems – the diagnosis of two previous “specialists” (if there were any at all) is complete nonsense.
Lambda probe(s) – either forgotten to connect, or damaged while unscrewing. In any case – if the car will run in such a condition, the expensive CO catalytic converters will be damaged very quickly.
Injectors, NOx system – additional investments of at least 1000 EUR are guaranteed. PWM of the valve of the oil pressure indicated around 30% – yes, there are problems. In a best-case – the valve itself has to be replaced (it leaks). Definitely – the oil and oil filter also has to be replaced, because this service could fill anything. Or even – not replace the oil at all. Because the car has a new owner, who should take care of anything.
Definitely, the spark plugs and ignition coils are not replaced. And nobody is even planning to do that. This also is the problem of the new owner. I’m not even talking about the replacement of any of seals, engine prophylactics. No, the engine has been taken from a car dump, totally unqualified masters have somehow installed it in the customer’s car, and – the job is done.
The customer should expect additional expenses of at least 1500 EUR to make the engine work as it should. At least 2 times more, if more than 2 injectors will be damaged or the problems with CO catalytic converters will start. Incomparably more, if it will turn out, that the cause of the oil pressure problems is worn-out bearing shells (unfortunately for these engines, if the problem with lowered oil pressure is not solved in time, such defects are common).
The most important of this entry: trust the repair and maintenance of your BMW only to specialized BMW service. Yes, it could be a small private service, but is very important, that the masters are specialized. Don’t choose the service, if you meet the serviceman of older age (more precisely – of any age), who complain, that the new engines (especially – petrol engines) are crap, that all car industry has finished in the Year 1980. With a probability of 99%, the education of these “specialists” also has been finished in the Year 1980.
If you purchase BMW, definitely bring it to the specialized BMW service center for diagnostics. It does not matter, you purchase the car from an individual of some service. Services are different – both with unqualified staff and blatantly fraudulent oriented. In this case, it would be enough to read the error messages (it should be done by INPA/ISTA – some “universal” tools will not fit!) to be clear that this “Frankenstein” should be avoided. It is clear, that that this current service will not be able to repair the car. Instead, if the owner of the car will drive to another service – the owner of the car will have to pay for the repair (eliminating problems, caused by this service), and the existing service will refuse any “warranty” if such was promised. And with great confidence, the next service will be blamed for everything, because “everything was perfect”.
p.s. repairs, which should be done to this engine immediately:
- replacement of the oil pressure valve, preventive maintenance of the oil back-valve, replacement of the oil filter and appropriate oil;
- monitoring of PWM of the oil pressure valve. If PWM does not reach 40 .. 45% – check the oil pump, inspection and cleaning the oil catcher, and finally – evaluation of the bearing shells (if the previously mentioned does not helps);
- solving the problem with the crankshaft and LPFP pressure data;
- encoding of the injectors;
- replacement of the spark plugs;
- solving the problem(s) with the Lambda probe(s), most probably – replacement;
- restoring the air-tightness of the inlet manifold – replacing the seals, possibly – replacement of CCV (cost of spare part around EUR 300);
- installation of the NOx emulator and replacement of the NOx system (if the customer wants to invest in it EUR 2500);
- registration of the NOx sensor and replacement of the NOx catalytic converter; re-adapting of the engine;
- evaluation of the real data of adaptations and injectors replacement of the damaged units;
- encoding of the injectors, re-adapting of the engine;
- cold start test. If any of injector is leaking (evaluation of mechanical efficiency of cylinders and fuel mixture);
- if any injector has been replaced in the previous step – it has to be encoded, the engine has to be re-adapted, adaptations have to be evaluated;
- evaluation of the density of misfires. If necessary, replacement of the damaged ignition coils. If any injector has an incorrect beam, (increased density of misfire in Stratified charge) – it has to be replaced. And again – encoding, re-adaptation of the engine.
The list is a “subsistence minimum” because it does not include potential problems of other systems: for example, DISA, VANOS, TEV, EGR, thermal management (electrical water pump, manageable thermostat), pass/fail tests of CO catalytic converters, etc. As the engine has been taken (without any illusion) from a dumpster – all kinds of defects and problems are possible.
