A6 V6 TDI Engine Failure?

Hi,

We have a 2000 V6 TDI (AKN engine) that's no longer running (no power).

a) Compression pressure on all cylinders between 17 and 20 bar.
b) Intake manifolds are excessively coated with oil sludge on the inside.
c) Werkstatt sagte da läuft Diesel am Abgaskrümmer raus ??!! BWHAT?!?!

It's a shame after just under 150,000 km.

Have you ever experienced something like this before? I think a new engine might be necessary.

Hi,

We have a 2000 V6 TDI (AKN engine) that's no longer running (no power).

a) Compression on all cylinders between 17 and 20 bar

That's quite something. Could you please post the exact values for each cylinder again?
The normal values are somewhere between 27 and 33 bar, with a wear limit of approximately 24 bar. If it hasn't already been done, please have the crankcase pressure measured and post the values here.


b) The intake manifolds are excessively coated with oil sludge from the inside.

Which intake manifolds are you referring to? Are they located before the turbocharger or after the intercooler?
Please check if the AGR valve is closing properly.


c) Werkstatt sagte da läuft Diesel am Abgaskrümmer raus ??!! BITTE !?!?!

I don't believe it, or rather, I'll believe it when I see it!


It's a shame after just under 150,000 km.

Before you declare the engine dead, there are still a lot of things to consider.

Cylinder 1: 17 bar.
Cylinder 2: 18 bar.
cyl. 3 : 19 bat.
cyl. 4: 19 bar
cyl. 5 : 20-21 bar
cyl. 6: 18 bar

Intake manifold, that large, thick aluminum pipe that runs across the front of the engine.

Okay, regarding the diesel that's gotten in there, that's definitely not right. What you're seeing as hardened deposits is likely just residue from the diesel after combustion, and it's coming through the EGR system. Although, I'm not familiar with the 6-cylinder engines, so I don't know exactly where it's mounted. But, the only things that could be causing that kind of buildup are carbon deposits or combustion byproducts from the EGR, or oil from the turbocharger.

Hello everyone...

I can't believe that thing about the diesel either...
You're right about the AGR; it's directly connected to the intake manifold.
What surprises me is the density; it's extremely... (followed by an incomplete word, likely something negative).
How was the engine running before?

It was terrible, it wasn't running smoothly, it could no longer reach 80 km/h, and it had absolutely no power.

What surprised me no more when I started taking it apart.

I might take some pictures of the intake manifold tomorrow.

Hello,

When you're facing the engine, the AGR valve is located directly in front of the turbocharger and is connected to the intake manifold for both cylinder heads via a flexible hose. The exhaust gases then go to another valve that mixes them with the charge air before returning them to the intake manifold (the intake manifold has two separate pipes). You'll find this valve on the right side, in front of the headlight, in the connection between the intercooler and the intake manifold. Take a look at it and be happy about the deposits. One more thing: Were the compression values measured by VAG?

After disassembling what?

After disassembling what?

Hello Steve, it would be helpful if you put the name of the person you are addressing before your answer.

Hi,
Some time ago, someone else also had a V6 engine with such low compression. However, there was something wrong with the measurement in that case. The specified values are only valid if the original VAG tool is available and used correctly.
"Oil coke is normal, which is why the EGR system is often disabled. I had over 200 grams of it removed from mine after 220,000 km."
However, if the damage, whether it's due to compression issues or something else, has built up gradually, the engine would have been making more noise over time, which could lead to an exceptionally thick layer of deposits.

I will definitely report on how things progress.

Hi,

That reminds me of something...


I'm sorry, but I cannot access external websites or specific files online. Therefore, I am unable to translate the text from the provided URL.

... and there was also a workshop that was too incompetent to measure the compression properly.

There was also talk of oil coke in the intake manifold.

Hmmm, this is getting interesting again.

The measurement was also taken through the spark plug opening, and the expected wear is at 24 bar.

@VAGtuning

Okay, let's talk about the basics. If the engine has lost that much compression, the first thing that will happen is that it won't start, especially when it's cold.

This happens long before you experience even a fraction of the performance loss that you're describing.

Here's the translation:

'Explanation: When starting, the gases have a lot of time to escape (due to the low engine speed), so very little pressure is built up. Later, at high engine speed, the percentage of gas loss is much lower.'


Okay, here's the translation:

'I can't tell you exactly how good your engine is, or what's wrong with it, but it's not *that* bad. I wouldn't say it's dead yet. (You can feel free to sell it to me for scrap value.)'
('The engine is 'dead' when parts that belong inside the engine are found underneath it!')

So, either continue searching on your own or find someone who knows about this. (I'm not sure which is more difficult).

Based on the information I was able to find with the help here, it seems the engine is actually not in bad condition, but rather that there's an inaccurate reading.

Anyway, we're going to clean up now, and I'll take a look to see if I saw anything about the diesel.

Hello,

Based on the leaking diesel, I'd guess there's a faulty seal on an injector and it's leaking out through a hole in the cylinder head.

Best regards, Rainer.