changed exhaust odor

Hello everyone,

I've noticed for some time that the exhaust smell of my TDI has changed significantly compared to before.

Initially, when the car was new, the exhaust smelled slightly pungent and sulfurous (I hope this description will help someone understand). Many DC CDI engines also have this smell.

Now, I can barely detect the sulfurous smell. However, I still find that the exhaust smell is different from that of a conventional engine.

IMO, the "defect" in the AGR (Exhaust Gas Recirculation) system has also contributed to a change in the composition of the exhaust gases. However, the change in smell was already noticeable before the AGR defect. The change has naturally occurred gradually over the years, not suddenly.

Are there any experience values here in the forum regarding how much nozzle wear affects exhaust odor? Can the odor change be attributed to nozzle wear or contamination? What are your experiences?

Best regards,
Alex

P.S. I also need to add that the engine is exclusively operated with diesel and has been operated since its inception. The oil consumption has hardly changed during the entire engine life and is approximately 0.75 l/15 tkm.

My 1z had somewhere around 180,000 km on the odometer when I noticed that two of the nozzles were leaking. After the nozzle replacement, the exhaust smelled like 'violets' again.
so, nicht mehr so extreme wie vorher! bertil stellte ähnliche Beobachtungen bei seinem 1z fest. Ich kann mir gut vorstellen, dass die veränderte Düsenform aufgrund von Verschleiß den Verbrennungsprozess und damit die Zusammensetzung der Abgase extrem beeinflussen kann!

According to Bosch, changes in the nozzle installation position within a 2° range also have an impact on emissions.

but something else. I don't know anymore by heart when and at which stages diesel became less sulfurous...

Could it be that the effect stems from this?

alex: Do you always use the same brand of fuel? I've noticed different smells at the gas station, and the exhaust also seems to correspond to the fuel mixture.
was was really awesome at the gasoline mill...

See you, Gremlin

After my AGR stopped working, the smell also changed noticeably for me.
Although I try to avoid smelling the exhaust fumes (due to the risk of cancer...), I now find the smell less offensive. More towards trucks or something
But actually, I think this whole "cancer" thing is just a rumor spread by the oil lobby or overly sensitive environmental groups.
I have a Steyr 15 tractor and after the "Russbehandlung" (treatment with "Russ"), all the farmers should die of cancer *g*.

Tagessuppe wrote:

I have a Steyr 15 tractor and after the Russ treatment, all farmers should die of cancer *g*

Do you also? No, not exactly, but there is a high rate of cancer among miners who work underground (especially in salt mines) operating wheel loaders and trucks. They drive back and forth all day in their cloud of smoke, and since diesel engines produce more exhaust when starting, rather than during constant driving.
In modern cars, where mine unfortunately no longer meets the requirements, I also think it's excessive.

Hello everyone!

Thank you for your responses. I didn't realize there were so many diesel exhaust pipe tamers in this forum! Okay, let's get this done.

Seriously though, you're really just involuntarily sniffing.

My question also had a small ulterior motive, because I think that my engine has been running a bit unevenly lately. I have the acoustic impression that one cylinder sounds louder when hammering than the others.
However, I was not able to identify any significant deviations when reading the idle regulator parameters. The values are all at a maximum of 0.4 to 0.5.

I hope that the changes in the exhaust odor and noise do not indicate one or more worn nozzles. IMO, this would be a bit early at 140,000 km.

On an American website, I came across the following article:
http://pics.tdiclub.com/pdf/injector_install_howto.pdf

This describes how to disassemble, dismantle, clean, and reassemble your nozzle holder combinations.
However, I can't imagine that the cleaning alone will bring so much. If the nozzles are worn, then cleaning will not help.
If soot tends to accumulate around the nozzle openings, it is removed due to the high exhaust gas flow velocity (similar to the principle of a high-pressure cleaner). Why should this immense amount of time be spent on disassembly, cleaning, and assembly?
Are there any other experiences to share? Where are the nozzle specialists?

Greetings
Alex

Upon request, deleted.

Hi Alex,
Let's go back to the smell.
The nozzles from Bertil's old 1Z are now in my
Motor, start your service.
After we had rebuilt the nozzles, there was also...
'A quick sample.'
It smelled noticeably less of Russia. Somehow, 'fresher'.
The old nozzles had 165,000 km on them.

Best regards, Rudi

There was noticeably less of a Russian smell. Somehow 'fresher'.

So, I have a 'Waldfrische' type air filter in the vacuum cleaner hose. It works!

Yes ... exactly so

And that even without the tree


Rudi

Thank you for your responses!

@diesel.gustav:

Quote:

The spray holes of the nozzles don't grow due to soot, but usually due to coke formation. In this case, the "high-pressure cleaner effect" from the fuel injection system no longer helps. Mechanical cleaning has already been done, provided it is performed correctly.

So, the expansion and cleaning of the nozzles actually do something.

Quote:

But didn't you recently ask about the procedure for starting the injection?

That's correct. The reason is that I am currently not satisfied with the performance of my engine and am conducting a thorough inspection. It also occurred to me that the test of the fuel injector valve, as described in the manual, did not function as described.

@Rudi:

Quote:

The nozzles from Bertil's old 1Z are now in my Motor, start your service. After we had rebuilt the nozzles, there was also... a "sniff test" It smelled noticeably less of Russia. Somehow 'fresher'.

What was the mileage on the used nozzles from Bertil's 1Z?

@all:
Is there a method to locate a faulty nozzle that is causing a louder cylinder hammering, without having to replace the nozzle?

Greetings
Alex

Hi Alex,


What was the mileage on the used nozzles from Bertil's 1Z?


between approximately 10,000 and 15,000 km. So, we were just getting started

Best regards, Rudi

Quote:

@all: Is there a method to locate a faulty nozzle that is causing a louder cylinder hammering, without having to replace the nozzle?

I believe it's also mentioned in a technical article: You should then successively loosen the connecting nut/nozzle connections so that no pressure can build up. Take precautions such as rags, glasses, etc.

donalexo wrote:

@all: Is there a method to locate a faulty nozzle that is causing a louder cylinder hammering, without having to replace the nozzle?

Hi Alex,

This, incidentally, is not found in a technical article. There is a stethoscope for listening to a motor (see link). With this, (assuming some experience), one can identify different engine noises.
So far, I've only used it to determine the ignition timing on my Jetta, but it should also work on diesel engines. It can also be used to listen for noisy valves, bearings, and other mechanical issues. Even today's "motoring gurus" still do this, but if you mention it in your workshop and you have a young apprentice as your master, then he will probably laugh at you.
But there are still mechanics who can (and want to):
http://www.truck-power.de/technik/pkw/klopfgeist.htm

Well, I also have a smelly engine. Can someone tell me where I can get cheap nozzles (I've already checked eBay)? Maybe I'll just leave the current sentence in until the timing belt replacement, and then replace it (then).

Best regards, WarLord

I have observed that faulty nozzles can be detected by a slightly sour odor. While it sounds strange, this is the case. I'm not sure if "slightly sour" is the best way to describe it. It's essentially the odor precursor to the smell of white diesel fumes.

Listening to bearings is something I'm quite familiar with from mechanical engineering. In fact, you really only need a steel rod that you place behind your ear on the skull bone, then you can listen to each individual bearing, or even cylinders. We used this method to check the bearings on lathes and milling machines (CNC). With a little practice, one can learn it.

Hello, this is Peter.