Running Culture: VP vs. PD

Hello,

Before I got my PD engine, I had read several times that these engines are supposed to run rougher than VP-TDIs.

However, from the driver's seat, my engine conveys exactly the opposite: it runs very smoothly, even after a cold start, almost like a gasoline engine.

You can only detect diesel knock during acceleration in the warm-up phase if you know it's a diesel engine and you know what to listen for.

When accelerating sharply, my Golf 3 with the AFN engine was particularly noisy and rumbled a lot, especially at low RPMs, and Christel's Ibiza with the ALH engine is hardly any quieter.
The ASZ Polo demonstrates here, in comparison, the characteristics of a gasoline engine: unfortunately, in terms of acceleration (until there is turbo boost), but especially in the form of less noise pollution.

And all of this, despite the fact that the 9N is partially poorly soundproofed: swirling dirt creates a tremendous amount of noise – almost Stone Age compared to the Golf 3 and Ibiza 6K.

Overall, I don't recognize the usual TDI engine sounds in this ASZ Polo at all – I've noticed it before, but I only just now thought about writing about it.

Can other users who have switched from a virtual private network (VPN) to a direct peer-to-peer (P2P) connection share similar (or opposite) experiences?

Hi Ulf,

While I'm not planning to switch to an electric vehicle myself, my experiences driving a workshop-modified Golf 6L with an ASZ engine confirm exactly what you're saying.

Best regards,

Jan.

And what about the people who switch from PD to VP?

I've always only had it to compare with the 100 hp PD engine in my colleague's Golf IV. It really runs much more smoothly than my ASV. However, below 1500 rpm, it tends to be quite noisy, but still pulls reasonably well, unlike the recently driven 130 hp PD Passat. My VP engine pulls in 5th gear from idle speed without being noisy.

Regards,
mcgregg

Switching from VEP to PD:

ALH engines from December 1998 and January 2001 were replaced with AWX engines in May 2003.

PD engines start faster, regardless of how warm the engine or the environment is; they require less preheating time, consume less fuel (~1.5 liters/100km), are less sensitive to heat than ALH engines; while the exterior ticking sound might be more metallic with PD engines, they are generally quieter (which is most noticeable, as Gremlin mentioned, at a drive-in like McDonald's); and PD engines tend to rev more freely.

The only PD engine that I found particularly negative was this 100 horsepower Euro4 candidate in a Golf 4.

The thing was louder than my ALH with its sports exhaust (2x90mm *grin*) and around 130,000 km on the clock, even when it had only 5000 km. Even my girlfriend noticed, and she's not really interested in cars at all.

Tip:
My car was actually making quite a racket because the engine cover underneath the motor had cracked and was hanging down due to heavy use during the winter. Once the new one was installed, everything went quiet again.

mcgregg wrote:

I've always only had the comparison to the 100 HP PD engine in my colleague's Golf IV. It really runs much more smoothly than my ASV. However, below 1500 RPM, it tends to drone quite noticeably, but still pulls reasonably well, unlike the recently driven 130 HP PD Passat.

(Side note)
That would be another comparison of a naturally aspirated engine with 100 hp versus one with 130 hp.
Normally, this is explained by the smaller loader in the ATD/AXR system, which runs at a higher speed and builds up pressure faster.
Could ATD/AXR drivers please share the boost pressure readings between 1000 and approximately 1700 rpm, either from a VAGCOM data log or read directly from the LDA (Lambda датчик)?

I'll be carefully monitoring my LDA over the next few days...

Coming from a Passat 35i facelift with a 1Z engine (90 hp) to a Passat 3BG with an AWX engine (130 hp), it's easy to see the difference. The 1Z was a prime example of noisy and shaky technology, while the AWX runs smoothly and confidently. The only thing that takes some getting used to on the PD engine is the somewhat uneven power delivery; the 1Z was much more consistent in that regard. However, when it comes to DIY repairs, I personally prefer the VP-37 engine because I'm more familiar with it.

By the way, I'll be switching back to VW technology for the winter season starting this fall. It will be an A4 with an AFN engine doing the job. On my first drive, I was quite surprised by how smooth and quiet it ran compared to my previous 1Z.

Despite this, I am quite convinced of the benefits of PD technology and appreciate its subjective and objective advantages.

Okay, I'd like to share my opinion as someone who uses AXR products.

However, I believe the comparison between the 1Z/AXR engines is somewhat unfair. It's not possible to compare a first-generation "rattle can" engine with a high-tech PD engine from the (second to) last generation. Therefore, I'm going to compare the loan car, a G4 TDI with 90 hp, that my relative provided me (VP of the last generation, engine code unknown). The VP G4 was very quiet when cold, but it really annoyed me when warm. With the AXR, you initially get the impression that the engine wants to shake everything off, but after just a few seconds, it runs as quietly as the VP. After the warm-up phase, it even becomes slightly smoother and quieter.
While the 1Z engine couldn't hide its origins during acceleration, the AXR remains relatively quiet. The PD TDI doesn't need to shy away from an acoustic comparison with a 4-cylinder gasoline engine (at least inside the cabin).
Recently, I went for a drive with a friend. He's only used to BMW inline-six engines (and those are really quiet). When we were cruising along the highway at about 180 km/h, he remarked that "the engine is surprisingly quiet for a 4-cylinder diesel." He seemed to be enjoying it, and I was surprised.

I believe that the comparison between the 1Z/AXR is somewhat unfair. I cannot compare a first-generation 'Rappelkiste' with a high-tech PD of the penultimate generation.

Okay, my comparison is here, and maybe it's a little unfair. But the topic was actually about running culture (VP <-> PD).

Hi,

Quote:

My vehicle's transmission engages in the 5th gear from idle speed without any noticeable droning.

Exactly my observation when comparing the ASV and ASZ. The ASV starts up smoothly from idle speed in fifth gear, while with the ASZ, nothing happened, and I had to shift gears; otherwise, the engine would probably have stalled.

"@Bertil: A 90 hp engine in a G4 can only be the ALH."

Best regards,

Jan.

I used to drive a Seat Toledo with the AFN engine. The car was really loud. It was the first generation Toledo, so the older model. Probably it was because the car wasn't properly tuned. I also drove G4 TDIs with 90 horsepower (VP and AJM engines) and a Passat with a PD engine, as well as an Audi A4 with the AFN engine. Maybe it's because the AJM engines were among the first PD engines. But the PD engines were louder. With the AJMs, you can really hear a distinct knocking sound, which didn't bother me personally.

Is this limited to 4-cylinder engines?
I can only compare the following models: G4 100PS / 115 PS PD and G4 90PS VP. If I were to rank these three, I would categorize them as follows.

Noise maker / Annoyance generator.

G4 100 hp PD (far ahead of any competition).
2. G4 90hp VP (ALH)
3. G4 115HP PD (AJM)

Okay, I have a direct comparison:

octavia ASZ to ALH.

The ALH engine sounds like a tractor and is really loud; it's a true diesel.
The ASZ (presumably a piece of equipment) is running like a sewing machine. It sounds oddly metallic, in a typical PD (possibly referring to a brand or type) way.
'Even inside, it runs more smoothly than the ALH engine, although that doesn't really bother me.'
When the window is open at the McDonald's drive-thru, I have to turn off the ALH (presumably a system feature) in order for anything to work; otherwise, nothing functions. It works better with the ASZ (another system feature). The driving experience is slightly smoother inside with the ASZ.
You can literally feel how smoothly it burns thanks to the pre-injection system.
When the shutters are closed, both are very quiet.
Both of them start up immediately on the first turn.
I find the ALH to be cold and somewhat brutal; at least those idiots immediately swerve off the road (as usual, they just run through red lights). It's quite close to the 'Homer' mentality. 'When I accelerate, I want people to think the world is ending.'
But somehow, it sounds more like a TDI than the ASZ.


Regarding the behavior below 1500 rpm, I unfortunately can't say much, as the turbocharger is sluggish until it reaches boost pressure. The ALH engine has automatic transmission, so it never operates at full load in that RPM range.

Hello,

For the 2003 model year of the Golf IV, some changes were made to the sound insulation.
see: http://www.michaelneuhaus.de/golf/golf4modjahr.htm
The engine noise of the TDI was reduced.

'I have one like this, and it only roars when you accelerate from low RPMs, just as McGregg described.'

The first PD engines with 115 hp were much louder and gave the PD engine a reputation for being noisy; they probably lacked the soundproofing mats that are now installed under the engine cover and hood. I once owned a Passat like that for a short time, and it was really loud, although I personally liked the noise from the outside.

Compared to the VP-ALH engine in the GIV, I noticed that the AXR had a less smooth operation during stop-and-go driving and at low speeds in first and second gear. The ALH would tend to jerk after being driven at full throttle, requiring significant use of the clutch.
In every other respect, the AXR is superior to the ALH, offering significantly more torque delivered earlier, greater power and elasticity, and a higher top speed.

The improvement in comfort in the later Golf IV with PD engine compared to a Golf III TDI is truly enormous. The steering, clutch, and gear shifting are all much smoother, vibrations and noise are drastically reduced, and the brakes are now appropriately sized for the performance.

For Ulf, switching from a powerful Golf III TDI, which is definitely a 'man's car,' to the new Polo with all its comfort improvements is likely a significant adjustment.

I've come to appreciate it, even though it didn't really play a role in the selection and purchase process.

Best regards, Marcus.

I've had both models living together in the same household for years: an A3 AHF VP and an A4 AJM PD, and I've treated them exactly the same – with the same chip and AGR (presumably referring to some kind of technology or feature).

The A4 is virtually silent and has very little vibration; the A3 engine clearly sounds like a diesel and also exhibits noticeable vibrations. Both engines start up relatively well when cold, and the subsequent running smoothness differs only slightly from that of the engine when it's warmed up.

The A4 starts delivering power much earlier than the VP. It really kicks in at just 1400 RPM, and it responds directly to throttle input. The A3 requires more revs to get going and exhibits a noticeable turbo lag. They had the same performance characteristics even before any modifications were made.

Best regards,
Uwe

Passat 35i B4 TDI (1Z) vs. Passat 3B TDI (ATJ):

Suit: The 3B accelerates faster, which is understandable given its significantly higher torque (over 100 Nm more) and 6-speed transmission.

Sound: In my opinion, the 1Z engine sounded more like a gasoline engine (based on the sound alone). There was no 'knocking' noise from the 1Z; the engine ran very quietly, but you could still tell it was a TDI. However, it was unfortunately noisy inside the car. The ATJ engine is quieter inside the cabin, but has a more pronounced, 'gruff' sound (a real beast).

Consumption: I only have positive things to say about my father's experience: With his driving style, the car doesn't consume as much fuel anymore. My own experience is more negative; when I drive, the car consumes over 0.5 liters according to the on-board computer, and after calculating it (the on-board computer is accurate), it uses more than the 1Z model. However, this is the only drawback of this vehicle.

Vibrations: These were higher in the 1Z engine. The ATJ engine runs much smoother at idle since it received a new mass airflow sensor (presumably because the EGR valve is still active).

'I personally don't find this comparison entirely fair. The 1Z engine in the same car (Passat 3B) would likely perform very differently and might even consume more fuel (or less, it's hard to say). Unfortunately, I haven't driven a VP engine in a Passat 3B myself, so I can't compare them. The 35i already had 174,000 km on the clock, while the 3B now has 120,000 km. I would have preferred to invest a little more in the old car, but unfortunately, I had an accident, and my mother then wanted a new car; eventually, I did too, because there are only worn-out 35i TDIs available. With its 70-liter tank and a winter fuel consumption of around 5.5 liters, you could drive approximately 1,200 - 1,300 km. The 3B indicates that you need to refuel much sooner.'

Best regards, WarLord.

Nuckelpinne_72 wrote:

Hello, For the 2003 model year of the Golf IV, some changes were made to the sound insulation. see: http://www.michaelneuhaus.de/golf/golf4modjahr.htm Quote: The engine noise of the TDI was reduced. "I have one like this, and it only makes that booming sound when you accelerate from low RPMs, just as McGregg described." The first PD engines with 115 hp were much louder and gave the PD engine a reputation for being noisy; they probably lacked the soundproofing mats that are now installed under the engine cover and hood. I once owned a Passat like that for a short time, and it was really loud, although I personally liked the noise from the outside. ...

The effect of the insulation mats should not be underestimated. Before the last inspection, I drove it without them (the plastic cover and the insulating ring, because I wanted to show the mechanic something...). It's amazing how much louder the engine becomes. In particular, all the noises coming from the cylinder head area become noticeably louder.