Kompressionsdruck zu gering 2,5 TDI V6 AFB | Posts 16+

Hi v6Motion,

I completely agree with Gaspedaluser. In the worst-case scenario, a worn camshaft may not be noticeable during a compression test. A worn camshaft should cause the engine to shake significantly.

v6Motion wrote:

According to VAG, the engine should not be able to run with these values

.

This saying should give you something to think about, because the people at VAG aren't entirely wrong about it. It might run, but with significant limitations (poor starting behavior, extremely slow...).

@Bertil

The engine is running normally and smoothly, with plenty of power and no noticeable loss of performance. That's what's so peculiar.

So, it looks like the only way to know for sure is to take a look – or is it possible to diagnose it from the outside?

V6Motion,

It seems you don't want to understand: everyone here is saying that something is wrong with the compression measurement!
You can go ahead and disassemble the engine if you want, and maybe even have someone tell you some fabricated measurements.
But if I understand correctly, you want to save those 10,000 euros. And the first step is to have the compression checked again somewhere else.
Everyone knows that a new engine performs well.

Best regards,

Hello,

You are talking about oil mist in the exhaust.

How much oil does it consume?

I recently had my engine (AFN) disassembled due to a head gasket failure at 160,000 km, and the original honing marks were still visible in the cylinder bores.
show very little wear.

If your engine is really in that condition, you would likely notice extreme wear on the piston rings and cylinder walls, which would be unusual for a vehicle with under 100,000 kilometers.
Furthermore, you would notice a very high oil consumption, as oil would leak between the piston rings and the cylinder bore into the combustion chamber, and conversely, combustion gases would leak past the rings and into the crankcase, reducing compression.

For your information, the AFN (presumably a pressure value) is now between 25-31 bar, and the wear limit is 19 bar.

Regards,

Faxes.

@gaspedaluser

'Tomorrow I'll finally get the car back, and then I'm taking it to another workshop - that's obvious. I understand the problem, but I haven't been able to test it out yet because the car has been in the workshop since last week.'

I will keep you updated on the results of the other measurements.


@Faxe

Due to the oil mist and extremely high oil consumption, the workshop only came up with the idea of measuring the compression. The entire amount of engine oil was gone after approximately 2000 kilometers.
It's a bit too much.

Hello V6Motion,

Due to the oil mist and extremely high oil consumption, the workshop only came up with the idea of measuring the compression. The entire amount of engine oil was gone after approximately 2000 km.


That's definitely quite severe and, in turn, suggests worn pistons/cylinders.
'Please definitely tell me what happened next!'

Greetings.
Gas pedal.

Hello,

What kind of oil did you use, and how often did you change it?
Is the mileage realistic, or could it have been tampered with to show a value over 100,000 km?

Best regards,
Christian.

@chris11

It must have been long-life oil. I always had the oil changed at VW whenever the service indicator advised me to do so.

After consulting with the mechanic, it turned out that the mileage, according to the centrally stored repair database, probably does match - at least not with a difference of 10,000 km or more.

I'm going to pick up the car now and take it to a different workshop. I have an appointment with the lawyer on Monday, and if the legal insurance approves, an expert can take a closer look at everything – then we'll know more.

hello
v6Motion

@ V4Motion,

You only started experiencing that problem after you installed your graphics card, right?

After that, it disappeared, right?

And it has reappeared again, right?

Since it was working correctly with a new KGE (charge air cooler) control valve, the defect must be in the KGE itself. The 270 mbar reading also suggests this. Therefore, have the entire KGE disassembled and inspected at A DIFFERENT WORKSHOP. If necessary, install the cyclone separator from the 132 kW TDI engine.

I also find such wear and tear to be very unusual. Unless someone put sand in your oil!

Regards,

Manuel.

Okay, great - I paid 238.00 euros, including the compression pressure test.
Proceed at your own risk!!!

I will probably have a pressure test done, regardless, so that it is clear which piston is leaking where.

If the pistons are actually damaged, a new engine will be needed.
Do you have any idea if I can install the AKE (132kW) without major modifications?
'The engine control unit is available, and I can also get the entire engine - including the turbocharger, fuel injection system, etc.'

Do you have experience with this, or would you prefer an AFB or AKN instead?

hello,
v6Motion

@Manuel

Your explanation is correct - the workshop doesn't know where the pressure in the ventilation shaft is coming from.
They're simply blaming the pistons for the damage.

I just picked up the car. They installed the oil mist separator from the 132kW model. If that's the correct part number: 059 103 464 B.

Now he doesn't smoke excessively anymore, and I can't hear any hissing when opening the oil filler cap. The workshop foreman said that the engine now has a pressure of 5-6 mbar in the crankcase, which is supposedly the maximum limit.

I have no idea what to do now - I'll visit a different workshop on Monday.

Sure, here is the translation of the text from German to English:

'Hello'
v6Motion

OK, a reduction from 270 mbar to 5 mbar is quite promising!

Keep an eye on it.

Even if the maximum limits are currently being exceeded, the question remains: how accurate is the measuring device? Who knows how many times it has been dropped, etc.?

I think the teacher is probably just trying to scare you! He can't admit that his diagnosis was completely wrong!

I would start by driving 1000 km and checking the oil consumption. If you're still having problems after that, then I would recommend taking it to a workshop again.

Regards,

Manuel.

Hi,

v6Motion wrote:

... I just picked up the car. They installed the oil mist separator from the 132kW model. If that's the correct part number: 059 103 464 B. Now he doesn't smoke excessively anymore, and I can't hear any hissing when opening the oil filler cap. The workshop foreman said that the engine now has a pressure of 5-6 mbar in the crankcase, which is supposedly the maximum limit.

What kind of workshop is this? First, they talk about a defective engine and quote a huge price, then they "only" replace the oil mist separator, and suddenly the fuel pressure is correct! :shaking head: If the fuel pressure is now almost okay, then the compression pressure values are certainly not correct - they "deliberately" measured them incorrectly!

Quote:

... I'll try a different workshop on Monday.

That's probably for the best.

I wish you all the best and I hope, along with you, that it was just a measurement error.

@Manuel

'The friendly person said it won't stay at 5 mbar for long. Let's wait and see. I just hope they refilled the oil – at least, there was nothing about it on the bill – I'll check tomorrow.'

I was thinking of going to the Bosch service center on Monday to have a pressure test done. Then I'll definitely know more - or does that not make sense?

@Bertil

They installed the oil mist separator for the 132kW model as per my request, and the invoice states 'installed at customer's request.' The engine has reached its wear limits. In other words, you're driving it at your own risk.


'Thanks to everyone.'

v6Motion

'As I suspected - the engine oil is below the minimum level. I think they're deliberately trying to make the engine break down. It's unbelievable.'

Crankcase overpressure cannot be detected when opening the oil filler cap. The car runs smoothly and doesn't smoke. Tomorrow, I'll go to a different workshop. Before that, I'll have them top up the engine oil – of course, at their expense. This is outrageous.

Are you aware of any wear values for specific mileage levels, which could be used to infer the actual mileage?
The high wear (if it actually exists) could be caused by using a powerbox for 40,000 km, but that's probably not the case.


Hi... I don't have any real data, just a single case study:

3 years of driving, 140,000 km. Mostly highway driving, with very few trips shorter than 100 km one way.
Mostly, the left lane.

The camshafts for the intake and exhaust valves looked like someone had been messing around with a welding torch on the surface... and then, at some point, the rocker arms broke.

(by the way, it was also an AFB engine).

Back then, due to significant pressure, Audi implemented a goodwill policy and covered 100% of the cost. Now, I've had a new engine installed (which would have cost me around 8900 EUR).

Before that, I only noticed that the oil consumption was quite high (requiring about 2-3 liters to be refilled every 15,000 km). However, my workshop never seemed to worry about it.

So... the first thing I did was to take out a warranty insurance, and I've been very grateful for that ever since.

Regards,
Felix.

P.S. Be glad that it's just the engine, you know how much a Tiptronic transmission for all-wheel drive costs?