ZR Change Intervals: What's New?

'first of all: no, I didn't use the search function '

'I had a conversation today with a colleague who drives a nearly new Fabia with a 100 hp PD engine (1.9L). He mentioned that the engine (MKB ???) supposedly has a timing belt replacement interval of 130,000 km. I vaguely remember reading something similar somewhere, but specifically for the newer 2.0L engines. Now, my questions are: Is that correct? That would be almost 1.5 times longer than before. Does the timing belt kit also fit the older PD engines, say from 2001 onwards?'

Hi Joerg,

Starting with model year 2004, even the remaining 105 hp 1.9L VW engine has a maintenance interval of 120,000 km. It is supposedly not possible to switch to longer intervals. However, Conti has been offering only one timing belt kit for the 8-valve PD engines for some time now.

I'm not going to guarantee that the Skoda 100 model is included in that list.
Mine has 90,000 km.
"Could you please inquire whether engines like the MKB (EU3, 100 hp) or the AXR (D4, 100 hp) have a maintenance interval of 90,000 km?"

You won't find anything using the search function anymore. The post was from your friend, and it, along with all the others, were deleted at their request.

Oops, 120,000 km?! I must have misheard.

'Hmmmm... Conti only offers one option now... VW says they are not interchangeable??? What's the difference then?'

joergs wrote:

... what is the difference then?

... Next question, please ...

Jörg, please check the service booklet; the intervals are listed there.
(It's already dark in the courtyard, otherwise I would get it again.)

My ALH has 120,000 km, and if I recall correctly, the ATD also has 120,000 km.

If my memory serves me correctly, the pulley wheels and their width were changed, which probably makes a conversion impossible.

CU Gremlin.

Gremlin wrote:

...if I remember correctly, the pulley wheels and their width were changed, so a conversion probably won't work.

My AXR engine has the widest timing belt currently available for the 1.9 TDI. However, I still only have a 90,000 km timing belt replacement interval.
Either something has been changed in the running geometry, or (based on customer experience), the maintenance interval for the new engines with this timing design has been extended to 120,000 km.
The AXR was introduced in 2001 with a new ZR drive system (enhanced ZR and PD components requiring less force). In the Golf/Polo, it replaced the previous ATD (which continued to be produced in other group models). This ZR is likely now used in all PD engines.
If the newer ATD engines also have a 120,000 km timing belt interval, then it can be assumed that the "banana tests" (product matures with the customer) were successful. Then, VW decided to extend the timing belt interval (with the timing belt introduced in the AXR engine) to 120,000 km. However, this only applies to new vehicles...

Hmmmmmmmmm...

Too bad... it would have been a significant extension...

Hi,

If it helps you:

According to the maintenance booklet, my 2004 Audi A3 also has a 120,000 km service interval.

@Bertil:

Quote:

In 2001, the AXR was introduced with a new ZR drive (enhanced ZR and PD elements with reduced power consumption).

Do you have any idea how this is supposed to work?
As far as I know, the vast majority of the power that goes into a particle deposition equipment (PDE) is used for ultra-fine atomization.

If suddenly less power is required, then, in my opinion, this can only mean one thing.
-> poorer distribution (I don't think so, because of EU3 -> EU4).
-> Improved "atomization efficiency" through cross-sectional optimizations, or who knows (but this should ideally already have been addressed as part of the basic development work for all powder deposition equipment).

Do you know any more details?

ulf wrote:

... @Bertil: Quote: In 2001, the AXR was introduced with a new ZR drive (enhanced ZR and PD elements requiring less force). Do you have any idea how this is supposed to work? As far as I know, the vast majority of the power that goes into a particle deposition equipment (PDE) is used for ultra-fine atomization. ... Do you know any more details?

No, not exactly.

I only know that PD 1.1 elements require 30% less force (and are also slightly smaller) than their predecessors. Furthermore, the EU4 standard was apparently only possible with these PD elements.
By the way, the 30% power saving refers to the power required for the ZR (presumably a specific device or system).

Most of the energy is likely "wasted" in the PD elements compressing the fuel. In my opinion, there is a lot of room for optimization there. Your "atomization efficiency theory" probably presented a significant problem in that regard.
The previous model was a hastily released technology, and with some fine-tuning, it's certainly possible to achieve a lot. With the AJM, the original weaknesses of the technology were exposed (e.g., the gearbox was too weak, the chassis was too unstable, the clutches were too weak, etc.).

Unfortunately, my AWX also has 90,000 km on the odometer.

The AVF engine, starting with the model year 04, already has a mileage of 120,000 km. The AWX engine was discontinued starting with the model year 04. (referring to the A4)

Bertil wrote:

The 30% power saving, incidentally, refers to the power on the ZR!

Hmja... but, as far as I know, the Northwest (NW) including the drive system was taken over by ATD. So, ultimately, the power saving must come from the PDE (presumably referring to a specific component or technology).

But how could a "simple" piston pump, which has the task of building pressure and delivering high-pressure fluid, suddenly save 30% of its power while maintaining the same stroke length (same swept volume)?
Reducing the diameter also reduces the conveying volume - which would mean that it was unnecessarily large to begin with...?

ulf wrote:

Bertil wrote: By the way, the 30% power saving refers to the power on the ZR! Hmm... but, as far as I know, the main unit and drive system were taken over by ATD.

Maybe!

Quote:

So, ultimately, the power savings must come from the PDEs.

Yes.

Quote:

But how could a "simple" piston pump, which has the task of building pressure and delivering high-pressure fluid, suddenly save 30% of its power while maintaining the same stroke length (same swept volume)? Reducing the diameter also reduces the conveying volume - which would mean that it was unnecessarily large to begin with...

Well, I wouldn't exactly describe the PD element as a "simple" pump piston.

You could potentially save a significant amount by reducing friction in the PD (positive displacement unit). The rocker arms are also different in the AXR compared to the ATD (which is another area for potential savings). Additionally, the pre-injection system with hydraulic damping (which also consumes a lot of power) has been modified.
I believe the "friction effects" at high pressures are significant. It's possible that you can save a considerable amount of energy simply by changing the geometry of the bore or the friction coefficient of the pump piston.
While I think 30% is a bit too high, let's just assume 15% for the sake of argument, and even that's quite a lot.