veränderter Abgasgeruch | Posts 24+

Hello, exhaust sniffers!

I went to the Bosch service today and brought in my nozzles (of course, in their disassembled state) for inspection.
The result was alarming: The nozzle holder combination with NBF is quite damaged, meaning the nozzle needle is slightly bent, resulting in an opening pressure of approximately 200 bar. But that's definitely not enough, because I could only see 3 beams coming from the 5 nozzle holes, the others were completely blocked!!!
Furthermore, the other 3 nozzles are so worn that the opening pressure has decreased to as low as 170 bar. That doesn't surprise me at all anymore.

Considering that the signal from the difficult-to-actuate NBF is used for the fuel injection start control, and there is a difference of approximately 30 bar in the opening pressure between the nozzle that provides the return signal and the "normal" nozzles, it is very easy to imagine that the combustion process is quite off.

Furthermore, I am really worried that the piston of cylinder 3 might have already been damaged, because the 3 jets are definitely going further than if the flow rate is distributed among 5

I don't want to scare you, but if you suspect unusual engine noises or knocking on a cylinder, I highly recommend having the injectors checked.
By the way, the Bosch man was very nice and didn't want any money at all. I then offered him 5 EUR for the coffee fund, which he readily accepted after a brief hesitation.
I think the price-to-value ratio is already okay, or?

Greetings
Alex

How many kilometers does your car have on it?

Best regards, WarLord

The nozzles had run for just under 145,000 km. That doesn't seem like a very large amount, considering what a new DHK costs!

Greetings
Alex

What did it cost (the DHK)?

Best regards, WarLord

donalexo wrote:

I'm not trying to scare you, but if you suspect unusual engine noises or knocking on a cylinder, I highly recommend having the injectors checked.

Hi Alex,

That doesn't sound very good.
Why is your NHG experiencing these problems after only 150,000 km? It seems to be completely blocked.
Have you installed any new ESDs now?

I can only agree with your statement regarding the engine inspection.

Hi Bertil,

Quote:

Why is your NHG experiencing these problems after only 150,000 km? It seems to be completely clogged.

I would also like to know that. But unfortunately, you can't get inside. In the worst case, I imagine that the wear on the needle valve is caused by abrasion from this, and that this abrasion may have already sealed two nozzle holes. But it's just a guess.

"Well, the friendly Bosch employee said: "Ohhh, the nozzle is hanging!"

Greetings
Alex

Hello everyone!

Re-opened this somewhat outdated thread in response to recent events.

My exhaust smell is now comparable to that of a new car or a CDI again. It now smells slightly pungent and sulfurous again, just like a direct injection diesel

Now, you're probably wondering what has changed?
1) Brand new nozzle holder combinations
2) Relatively new, uniform pressure valves (approximately 37,000 km) on the fuel injection pump

If your TDI smells like a diesel engine, a tractor, or even Russian diesel, then you should probably pay attention to the components mentioned above

Your oil consumption should, of course, be within the normal range, otherwise even the best injectors won't be able to ensure "clean" emissions.

Greetings
Alex

Hello,
Here's the translation:

explain to a non-professional mechanic what nozzle holder combinations are! ?
I can't understand this at all.
Of course, I also have my concerns about the 300,000 km old nozzles, even though I can't afford to spend €400 on new ones!
Thank you very much.
Best regards
Wurstblinker

Hey Alex

You still owe us a sum

What did the 4 duets cost? Did you get the complete ones from AT, or did you have them broken down/have them broken down ???

m;
...and thinks about it carefully.

I think I finally get it!
it's simply new nozzles!

Double Post Martin

Okay, let's talk about it... How should a TDI smell?

I bought it used with 140,000 km on the odometer...it of course doesn't smell like roses or violets

It smells more like... chlorine or something similar.

It's a 2.5 V6 TDI AKE.

I am generally looking for lost fuel...something like an injector could also help the car 'drink' more fuel...


Can someone describe the 'optimal scent'? Lazy Eggs (H2S) or Gucci?

{Okay}... How should a TDI smell?

Polarlarry wrote:

... It smells more like... chlorine or something similar.

You seem to have a cheerful disposition... Smells describe ....

So, a slight chlorine-like odor is normal.
If the DI smells strongly of old tractor exhaust (i.e., soot), then I would consider optimizing the combustion process.

@Polarlarry:

Lazybones is a gasoline.
Gucci a rainbow-colored Diesel ...

Seriously, something like chlorine or acidic is a proper scent for a direct injection system. There has really developed a characteristic smell, you can often smell the fully loaded tractor on the track long before you see the smoke cloud .

But if it becomes smoky and sticky, something is usually wrong.
As Bertil already wrote.

donalexo wrote:

Hello everyone! Re-opened this somewhat outdated thread in response to recent events. My exhaust smell is now comparable to that of a new car or a CDI again. It now smells slightly pungent and sulfurous again, just like a direct injection diesel Now, you're probably wondering what has changed? 1) Brand new nozzle holder combinations 2) Relatively new, uniform pressure valves (approximately 37,000 km) on the fuel injection pump If your TDI smells like a diesel engine, a tractor, or even Russian diesel, then you should probably pay attention to the components mentioned above Your oil consumption should, of course, be within the normal range, otherwise even the best injectors won't be able to ensure "clean" emissions. Greetings Alex

donalexo:
Okay, so, das interessiert mich jetzt auch noch mal. Why did you replace the equal-pressure valves? Just on suspicion? Could you also detect a difference just by changing the valves?

/Jan

Hello Jan03!

Unfortunately, I am unable to adequately differentiate between the (partial) effects of changing the pressure valves and the nozzles, as I performed both changes in a single operation.

Certainly, it would have been essential to change only one thing and then observe the result in order to arrive at an accurate diagnosis.
Now, unfortunately, due to time constraints, I had to replace both the pressure-regulating valves and the nozzles simultaneously.
In summary, a significant difference was observed.

My suspicion of a faulty pressure regulator stemmed from the fact that I had recently installed other nozzles for testing purposes, which were also used, but had a lower lifespan. With these nozzles, I observed the highest idle run regulation values on the same cylinder, and I continued to observe a slight knocking noise on one cylinder.

With the new nozzles and equal-pressure valves, all cylinders are now much closer together in terms of idle speed control, and the knocking has also disappeared.

The ideal diagnostic method would certainly have been to replace each pressure valve individually and then measure the change using a VAG-COM and also listen with my own ears.
But the associated time commitment cannot be justified, especially when one relies on their car daily and has very little free time.

Greetings
Alex

Hello Donalexo

Well, that sounds promising. I also have new nozzles and still have the slight knocking and uneven idle speed control. I was already thinking that a new pump is needed.
Where were the prices still? Around €40-€50 per piece, right?
Do the tubing connections also need to be disconnected on the nozzle side, or can they be moved far enough so that the valves can be replaced (one was difficult to get to seal again after replacing the nozzle)?

Greetings
Jan