The car owner with the N53 series engine got in touch with me. The diagnostics indicated that the car has significant problems with the injectors. Almost all of them are leaking in closed condition (1 leaks for warm engine, 3 – for cold engine), one injector has significant problems with fuel atomization, and several – have extreme flowrate corrections.
The car owner took out the injectors from the engine block and informed me that the situation was quite strange because a little while ago, these engines were purchased as new.

What do we see in the picture?

First conclusion – either these are not new injectors or have been “lying” in some warehouse for 6 .. 7 years. All injectors are with the actual 11th release. But all of them were made in 2015, which means – 7(!!!) years ago.
Let’s look closer at the injectors. Here, for example, the injector No.1:

And in this image, I will mark parts to which you should pay particular attention:

It looks like the injector has been cleaned!
And now, let’s check another part of the injector:

Pay attention to the rust on the technological “covers”:

It is impossible to determine who and when “cleaned” the rust from the front part of the cap (that obviously happened when the injector was touched by hands), but it is clearly visible – the caps have started to rust. That is normal for injectors, used for 7 years. But the most exciting part is that the same welding seam has also been made in the region, previously inspected.

Here, two identical made seams, but completely different appearances! Of course, VDO in their factories is not polishing the bottom seam; this also gets rusty over time.
I have no doubt that somebody has “worked” on these injectors. If these injectors have got in the hands of such “specialists”, with a probability of 99%, I can anticipate – they are either “cleaned” or “refurbished”. And at this moment, all questions, what happened to these injectors, are useless. Unfortunately, several thousand EUR are paid to the fraudsters and wasted.