Quantity deviation after injector replacement

Hello everyone,

"On my Passat 3C (CBBB 2.0 TDI with 170 hp, manufactured in 2010, with 98,000 km mileage), I observed a fuel quantity deviation of >2mg on the first cylinder when the engine was cold. The engine also vibrated slightly. Once the engine warmed up, the deviation decreased to 0.xmg." While idling, I noticed an unpleasant smell and a little smoke coming from the exhaust (it smelled like unburnt fuel).
I then purchased a revised nozzle and replaced the injector on cylinder 1 (including the necessary adaptation/calibration).

The calibration values for this cylinder are now set to 0, and the amount of deviation was 2 when it was cold, and has decreased to 1.4 when it is warm.
He didn't twitch, and there was no noticeable strong odor.

The question is: After the initial calibration, must the quantity deviation be immediately perfect, or is it initially different due to the lack of long-term data?
It's a silly question, but I've driven mostly gasoline cars in recent years and have very few memories of those values...

Thank you very much!

Hi,
The calibration values are adjusted during operation. It requires a certain amount of mileage. 1000 km might already be enough.
The margin of error is strange, as it has become significantly worse with the change. If it doesn't get any better and the compression is correct, then the injector is no good.
hg
Herbert.

Thank you for the quick response!

I still need to measure the compression. If that's okay, I'll try to get it running first. The values are not critical.

Hello everyone,

Unfortunately, we haven't been driving the car very often lately, but we have still noticed a significant oil dilution problem.
I changed the oil right before installing the injector. Since then, I've driven 2500 km, and I've noticed approximately 1 liter of diesel in the oil again (within those 2500 km, there were vacation trips of 1000 km, and many of the routes are longer than 20 km, so it's not just short trips).
As far as I can tell, the only way to access the injectors on that engine. Is that correct so far? (There's no tandem pump or anything like that, as with the PD models.)

I then removed the injectors and sent them to Biberach for overhaul. While doing so, I noticed that all the nozzles were full of diesel between the O-ring and the copper ring. So far, I haven't noticed this on any of the CR-TDIs, although I've never really paid attention to it.

I've attached a picture here. You can clearly see on the fabric that diesel fuel (yellow) was applied to the lower part.

Is that correct, or have I found the error with that?

If that's the case, are there any other options for this engine to prevent diesel from getting into the oil?

Thank you very much!

Hi,
What does the F**** D************* in Biberach say about the problem?
Completely neutral, if it were my car, I would have bought a refurbished or new injector from VW (just one, given the mileage). But definitely not sending the other, presumably good, injectors to the Swabian region just to have them "tuned up."
The miraculous increase in oil consumption happened spontaneously after replacing just one injector, so it must be related to that. The diesel injector marking may have been created during the removal process.
hg
Herbert.

They should be receiving the injectors today. Therefore, I have no comment on that at this time.

Is their reputation really that bad? I haven't found much information online about maintenance technicians, so it's proving quite difficult to distinguish the good ones from the bad.

Is there a better option available here? The Bosch service center in Mannheim can only perform inspections, but not revisions.
If better providers become known, I would adjust the order so that they only perform a review, but not a revision.

We had experienced oil dilution before, but not to this extent. I initially attributed it to the relatively short distances I was driving (at the beginning, my wife was driving up to 120km per day, and then she changed jobs, so we only kept the car because of the caravan).
I wanted to have everything checked, mainly due to the uncertainty.

Thank you very much!

Brief update on the matter:

The nozzles have been returned and are currently in perfect working order. According to VCDS, the quantity deviation is between -0.4 and +0.2.
The learning parameters are initially set to zero and need to be re-trained.
"Seals and copper gasket are new. Test report from the Bosch test bench is included, along with a new IMA code." So far, so good.

Unfortunately, one needs to be careful when considering engaging with this company. We had email correspondence beforehand regarding the maximum costs, etc., and I also sent a cover letter explaining that, due to the relatively young age of the equipment, I suspect that only 1 or 2 nozzles are defective, and that I want to find out through the inspection whether my assessment is correct.

If you select the option that allows them to repair directly, then they will automatically replace everything they can, without further inspection. This means you won't know if the injectors were actually defective. What exactly does the statement about the maximum [value/limit] refer to? The lady couldn't explain the cost to me either.

Now we have to wait and see whether the oil dilution will continue or not.

Thank you for the feedback .

cksIT wrote:

Hi I then removed the injectors and sent them to Biberach for overhaul. While doing so, I noticed that all the nozzles were full of diesel between the O-ring and the copper ring. So far, I haven't noticed this in any of the CR-TDIs, although I've never really paid attention to it before. I've attached a picture here. On the cloth, it is clearly visible that diesel (yellow) was smeared in the lower part...

What stands out to me in the picture are three grooves, but only one installed sealing ring.
If the others have already been dismantled, then diesel fuel was likely also used to verschandeln the nozzle. If the other sealing rings were not installed, that could also explain possible errors .

No, only a sealing ring is installed on the nozzles; I have no idea what the other grooves are for.
Both the revised and the extended versions only had one O-ring, and the Elsawin documentation also only shows one. We can therefore rule that out.