Engine Problems: Black, Smoking Crankcase Ventilation

Hello everyone,

I could use your advice again... (The search function couldn't directly help me.)

First, let's talk about the car:
Golf3 AFN, 230,000 km, no chip tuning or modifications, original injectors, coolant level stable and clean, turbo boost hose seems to be leak-free, ...

I'm having a relatively complex problem with my AFN.
'Firstly, the engine is leaking oil from the lower outlet of the crankcase ventilation system (see picture). The oil seems to be being forced out from here. Currently, I'm leaving a 1-2 cm oil stain on the ground in front of the house every day.'

Now, the bigger problem.
The engine starts to produce a lot of black smoke under higher loads, especially the first time after starting the engine. This starts above approximately 2000 RPM and 0.5 bar of boost pressure. There's already a significant amount of carbon buildup visible at the exhaust pipe...

I did a small compression test today. I used 3rd gear, a steep downhill slope, and took a compression reading every ~0.5 seconds. I couldn't detect any differences.
When the engine is idling, and I remove the oil filler cap, I can feel relatively strong pulsations. A piece of paper (like a paper towel) placed 5 cm away from the center of the opening starts to flutter significantly (2 cm).

I am now imagining the following scenarios:
A) One or more piston rings or valve stem seals are broken, which causes higher pressure in the ventilation system. When I ride with higher loads, so much oil comes out through the ventilation system that it makes a gurgling sound. This is also the reason for the oil loss.
B) The pulsation seems normal (I'm not an expert), and in my case, it's likely that one or more fuel injectors are faulty. This wouldn't be surprising given the mileage.
Oil leak due to a damaged seal on the nozzle.


I would like to hear your opinions on A) or B). Or maybe even a C????
Tips and tricks, what else can I check?

More information:
The car has mostly been driven short distances (less than 10km) for the past 2 months. Oil consumption has been low so far (less than 1 liter within the change interval), but the current consumption is unknown. The engine starts well and responds well to acceleration; the performance seems normal under partial load.
I'm not putting it under heavy load right now (not that it's going to break!), so I can't say for sure if it's still performing at full capacity.

http://www.rushseven.com/Diesel.jpg

Best regards and thank you.
Markus.

Okay, here's some information about the image.
The fitting is located to the left of the oil cooler filter.
A large portion of the deposits are caused by the mileage.
The oil comes out from here, runs down the front of the engine block, into the cover underneath the oil pan, and then drips out through the opening in the drain plug.

Hi, have you checked the boost pressure?

It would be interesting to know if the boost pressure is actually fully achieved and how long it takes to build up the boost pressure. This could be the source of the 'russproblem' (presumably a specific issue).

Can you measure the compression of your engine in bar?
It is normal for the pressure to increase and decrease during the operating cycle.

Actually, the pressure in the engine head is increasing, but not significantly. However, based on your description, it's difficult to say exactly how much it's increasing.

It is fundamentally possible for piston rings to be defective, allowing combustion pressure to leak into the crankcase. However, in such cases, the engine's power output is usually reduced.

My suggestion: Measure the compression, record the usual engine parameters, and publish them. That way, you'll have more information and won't have to guess.

Best regards, Jochen.

Hi,

I haven't measured the boost pressure. Since I noticed this issue (which, in my opinion, happened quite suddenly), I've only been driving with the most economical fuel setting.
I'll definitely do that sometime soon. I have an LDA installed, so it should be fairly quick.

I'll also be doing a compression test. I need to find a workshop that can do that (through the glow plug housing, right?). Most larger garages should be able to do it.

Thank you for the tips...

Until the days...
Have a nice weekend...

Hello everyone,

I picked up my car from the dealership today.

The compression test (performed via the glow plug threads) indicates the following:

Mileage: 231,474 km

Cylinder 1: 18.9 bar.
Cylinder 2: 20.3 bar.
Cylinder 3: 19.5 bar.
Cylinder 4: 19.2 bar.

According to Volkswagen's statement, everything is absolutely fine.
What do you say?

On the way home, I checked the boost pressure.
I repeatedly accelerated in third gear, flooring the accelerator.
The boost pressure increases as usual, oscillates above 1.1 bar as always, and then settles at 0.9 bar at high engine speeds.

Perceived performance: Well, I think it could have been a bit better.

Exhaust fumes: Oh dear, the amount of smoke coming from the exhaust increases quadratically with the engine speed. At 4000 RPM, I can barely see anything through the rear window. It's really disgusting. The car has never smoked like this before.

I checked the crankcase ventilation system after the ride.
I unscrewed the hose that connects to the black container on the valve cover; there's a slight oil film inside. I think that's normal for a car with 230,000 km.

What I'm planning to do now:
- Da der Ladedruck passt denke ich nicht das es an einer undichten Verschlauchung zwischen Turbo und Saugrohr liegt. What do you think?
- I suspect it's either the nozzles or the HFM (High-Frequency Manifold).
Can I check the HFM (High-Flow Mixer)? For example, at a constant speed of 100 km/h and xyz RPM, approximately xyz kg/h should be measured. Or is there an adaptation value or something similar that I can use to determine something?

Regarding the oil leak:
It's definitely a leak from the crankcase ventilation hose connection. I cleaned everything thoroughly, and now, after a few kilometers, you can see that it's leaking out near the flange (see the picture above).

Until the days...

Markus.

Regarding the exhaust: the EGR valve is stuck open. Solution: seal the EGR valve with a metal plate.

Regarding the oil leak: the lower connection of the KGE (turbocharger coolant expansion unit) is sealed with an O-ring, and it looks just like the quick-release couplings on the charge air ducts of newer TDIs. Solution: Pull out the clip, remove the pipe, and replace the O-ring with a new one.

Best regards, Nebelwerfer.

Due to the compression pressures. They are quite low. 19 bar is the minimum for your engine.

Well, just look at his mileage. Other engines are often finished much sooner .

"There are also engines that still have pressures exceeding 24 bar. Also, 230,000 km is only a moderate mileage for me."

Also, for me, 230,000 km is just an average mileage.

With a reasonable driver.

Hi,

Thank you for the answers.
Die AGR werd ich mir heute oder morgen anschauen. I was actually planning to do that.

Regarding compression:

The values are listed above.
Who can tell me from a reliable source how much iO and niO are?
My VW mechanic said the AFN engine has a top-notch fuel pressure of 22 bar, and the lower limit is 16 bar. So, I'm still within the acceptable range.
Suddenly, they're talking about 24bar.

Does anyone have definitive values for this, or is that information available somewhere on the internet?

Thank you.

Hello.

As far as I know, 19 bar is the minimum. The 24 bar was just an example; there are also engines with 230,000 km that still have such a high compression ratio.

I just found my 'Ich helf mir selbst' book again after a long search.

It also states that the minimum pressure is 19 bar.
Well, now good advice is expensive.
Maybe it's finally time to buy a new car after 6 years and 180,000 kilometers.
Putting money into a car/engine when a replacement engine might be needed soon doesn't really make sense.

Quote:

Can anyone tell me, from a reliable source, how much iO and niO there are? My VW workshop said that the AFN has a top iO pressure of 22 bar, and the minimum acceptable pressure is 16 bar.

So, I'm still within the acceptable range.

Who can confirm to you, from a reliable source, that the measuring device of the is accurate, or that it was measured correctly?

Given the very small pressure differences between the individual cylinders, I would cautiously assume that it might still be okay.

Depending on the volume of the air path from the ZK (control unit) to the measuring device (possibly with an adapter or similar in between), the compression ratio decreases accordingly, which means the actual compression pressure is higher than the measured pressure. Therefore, it is possible that your is correct, even though the wear limit is 19 bar.

How did you measure the boost pressure?

If the MSTG (presumably a pressure sensor) now has a faulty reading, displaying 1 bar, but the actual pressure is only 0.7 bar, it adjusts to the real value of 0.6 bar, which works perfectly with the VTG (presumably a control system). (These are hypothetical values.)

I can easily test my pressure sensor because it should produce at least 0.6 bar at 4000 units, which allows me to always calibrate and check if the sensor is still working.

Take a mechanical LDA.


Nozzles are also a good tip - and you'll always find a buyer for any 190 bar 205 nozzles you might have bought unnecessarily. The 1Z faction will laugh about it .

m;

I measured the boost pressure using a mechanical VDO gauge. I've had it installed for years, ever since I had problems with the VTG adjustment.

I'm going to check the AGR today.

Until the days...