AFB Engine: Worn camshafts, broken rocker arms.

...and pestle.

Hello everyone.

My A4 was in the workshop again last week; they wanted to fix the idle fluctuations after a cold start (see my own thread here in the forum) by installing a new engine block. (this is the 2nd new engine within 2.5 years).

The examination revealed that all four camshafts had sunk into the cylinder heads by more than 1mm in some cylinders. Eight out of 24 lifters were completely broken, ten more were severely worn, and three rocker arms were broken into multiple pieces.

And I wondered why the box was making so much noise...

So, the (previously ordered) engine block has now been installed, and the cylinder heads have been completely overhauled; thankfully, all the small parts have been found and haven't disappeared into any crevices.

Now it's running quietly again, and the power is developing smoothly and evenly.

My question to the experts: How is it possible that so many parts in the engine are broken, yet the thing still drives reasonably well?
What is the reason for all these defects? I am absolutely certain that I have never driven the vehicle with insufficient oil or without any oil; furthermore, the bearing shells of the main shaft are all completely undamaged.
Shouldn't a workshop (a specialist Audi service center) have noticed something was wrong with the cylinder head when sealing the valve covers, especially since I had pointed it out to them?

Thank you for any feedback.

Stefan.

P.S.: By the way, the idle fluctuations after a cold start are still just as pronounced as before...

Hi,
Why are the parts breaking? I haven't found an explanation yet, but it's probably not uncommon.
The fact that it runs relatively smoothly despite its condition is probably due to the four-valve design, or perhaps a favorable distribution of defects that hasn't completely disabled one or even two cylinders firing in sequence. If one or both of the intake or exhaust valves of a cylinder fail to open, the cylinder doesn't completely stop working. However, I would have expected a significant amount of smoke, especially under full load. While the engine control unit can detect the overall lower throughput, it cannot determine that the air is being distributed unevenly among the cylinders.

The vehicle produced very little smoke, but the sound of the engine was extremely loud, and the acceleration up to 3rd gear was quite slow. Gait is very unsteady.
In my opinion, the consumption and top speed were not particularly different from what I was used to.

The V6 TDI engine, even when in perfect working order, doesn't run particularly smoothly; in certain RPM ranges, it tends to run unevenly.

Has anyone else in this forum had experience with broken or damaged internal engine components?

Or, to put it another way: what is the reason that the vast majority of V6 engines (AFB and AKN) have been replaced before reaching the 100,000 km mark?
Is the entire model line unreliable, and are the later versions significantly more durable?

Even though I'm not completely satisfied with the engine, it has never let me down; it has always started, and I can't complain about that.

Stefan.

Hello Stefan,

I am currently looking for an Audi Quattro V6 TDI, and during my search, I have already come across 5 similar engine failures. Apparently, the main years affected are 1998-2000. Apparently, a better camshaft is installed starting in the year 2000.

I'm now completely unsure whether I should even buy a car like that.

It's probably best to buy one with engine damage and rebuild the engine from scratch. At least you know the engine is broken, and you'll also pay less.


How did your repair go under the good-will warranty?

What year is yours?

Okay, before MJ2001 and at least... I wouldn't buy another AKE.

Mine is a 12/98 / MJ99 model with a VIN ending in <200000 (so, just before the facelift) and currently has 155,000 km on the odometer.
Well, that depends, but the engine is now new again.

The workshop has invested approximately 50,000 euros (!!!) in the machine; that's almost 10,000 euros more than the original purchase price was at the time...

However, neither Audi nor the VVD have complained so far; everything has been replaced three or four times (see my other threads), and the original defects are still present.

What I don't understand is that Audi hasn't yet intervened, someone offered 5,000 euros above the list price and requested never to buy another Audi/VW again...

But it seems that the gentlemen and ladies there are also sleeping soundly; the workshops are, after all, quite noisy. *sigh*

Fortunately, the fourth one is gradually arriving. Removing the V6 TDI engine, as I'll probably need to replace mine soon too...

Stefan.