Quite often we hear – the situation with repair specific of BMW is critical. The situation with BMW specialists in the area of engine and diagnostics – critical.
I agree. But sometimes also the user of the cars are the ones who blame. This entry is another example, which confirms it.
In my blog, I have mentioned numerous times – do not purchase “restored”, “repaired”, or “cleaned” piezo injectors! These injectors can not be cleaned either repaired! But still, there are BMW users, who do the opposite direction. The reasons can be different – hoping for the luck; the desire to save; disbelief in the “pessimistic diagnostics specialist”… The true cause is known only to the current BMW user itself. In this entry – an example, how does the diagnostics data look when the injectors are “repaired” in such a way.
The owner of the BMW with N53 series engine approached me. He has installed “restored” injectors, which were bought from an if large and well-known German company (I will not publish the company’s name because I have no option to check the relevance of the facts for 100%).
The engine sometimes vibrates; there are misfires. The NOx system is repaired and in working order; the Stratified charge is in use – everything should be perfect.
I received the diagnostics data; the incorrect values are marked with red.
First suspicious symptom: DME has switched the engine in Mapped mode with a temperature of 80oC because, in increased temperature, it has noticed the incorrect performance of the injectors:

Here, the bank adaptation by the temperature segments confirms that in the last two temperature segments, both banks have had problems with the fuel mixture stability:

Here, the basic data of the fuel mixture. Control probes of both banks confirm a rich mixture; the Offset LTFT data of the 1-st bank shows leaking injectors:

Directly after starting the engine, the injector problem of the 1-st bank can be seen:

Also, the NOx sensor confirms fuel mixture problems. As we see, the average fuel mixture really is rich. The exhaust temperature – strongly increased. It means – a large part of the fuel is burned in CO catalytic converters. Logically – the CO catalytic converters are getting overloaded and damaged!

Here, the chemical efficiency tests of injectors in Homogeneous mode. As we see, deviance from the ideal of injectors No.2, 3, and 4 are huge!

Here, the injector leakage test results for idle, Stratified charge:

In this menu, I marked all test values of the injectors as incorrect because there is complete chaos! It is hard to find any injectors, which were not leaking or that hasn’t have atomization problems. For example, the injector of cylinder No.2 leaks very strongly, but the atomization of injector No.3 is critically bad. This injector is pouring out, not injects the fuel. The injector of cylinder No.5 also strongly leaks…
Here, the results of the chemical tests of injectors in Stratified charge, in conditions of partial load:

Injectors No.2 and No.3 have flowrate problems.
Here, the live data of the injectors. In Homogeneous mo, for the injectors are both Offset, and flowrate corrections applied, the parameter scattering of the injectors – increased:

Injectors No.3 and No.4 have problems with a reduced flow rate.
Mechanical efficiency of cylinders:

Complete crash in both banks. In addition, it’s not a situation – (only) one injector in each bank is leaking. Almost all injectors have problems! Injectors No.1 .. 3 are leaking; injectors No.4 and No.5 also have problems.
The injectors leak so en mass that even Lambda values in both banks in Stratified charge are strongly decreased:

And finally – the error message list.

Here, mechanical efficiency in idle, Stratified charge for cylinders No.2 and No.3 has been increased even by the injector opening time reduction for 50%. So, the injectors have leaked so strongly that the injected amount of fuel has been at least 3 .. 5 times larger than it should be!
In this example, you can see that ALL injectors deserve a place in a trash can. Unfortunately, the car owner has wasted 1000 .. 1500 EUR for these injectors and their replacement. Even worse – all exhaust system has suffered very badly, and if the problem is not solved immediately, he can expect expenses for at least 3000 EUR additional costs.
The owner of the car turned to the seller of the injectors with reclamation and my diagnostics report; the seller has offered a “bonus” – free “diagnostics” on their injector stand and replacement of the “defective” injectors with others – also “restored”.
This offer shows the complete incompetence of the seller of the injectors:
a. the injector tests on the stand are performed at room temperature. In real conditions, the injectors work in temperature -30 .. 120oC;
b. in laboratory tests, it is not possible to evaluate the atomization of the fuel;
c. in laboratory tests, it is not possible to see sporadic defects;
d. in laboratory tests, it is impossible to repeat other real conditions – for example, changes in the Rail pressure, etc.
Such laboratory tests are completely useless!
DME live and test data confirm uncountable problems for all injectors; it makes no sense to try to find any usable injector from this pile of garbage.
Is there anyone else who would like to try “restored” injectors?