AVF Engine Differences: What to Know

Hello everyone.

I have a question for the specialists here. I currently have the opportunity to buy an AVF engine with 32,000 km on it.

The engine comes from a Passat manufactured in 2001. My Audi A4 was manufactured in 2004.

Does the engine fit directly, or are there any things I need to be aware of?

Ich habe schon gehört, dass die PDE Elemente anders sein können. Wanything else?

Thank you very much in advance, and best regards from Switzerland.

Tobias.

Hi there.

The engine numbers would be interesting...

I suspect that in practice, there won't be any noticeable differences, and one motor will run just like the other. Of course, I'll put them side-by-side and compare them to make sure everything is truly identical.

It's possible that the PD elements are being changed; there are constant modifications to the series due to stricter emission standards and changes in suppliers.

Hello.
Thank you for your reply. Unfortunately, I don't have the engine number. There are certainly differences, such as the belt drive system, which isn't the same on all engines, and the timing belt tension (hydraulic or friction-damped). The belt for the auxiliary components can probably be modified, but that will of course be checked before installation. My main concern is about the PD elements, specifically whether the older engine would simply work with my control unit (which would be ideal for chip tuning), or whether my car would at least be compatible with the control unit from the "newer" engine, which is 3 years older.
Best regards,

Hi there,

I would be very cautious here; the engine codes might appear the same, but the actual engines can still differ.

"I believe there were differences in the AFN engine block depending on whether it was installed longitudinally in an Audi or transversely in a Volkswagen. Also, some mounting holes might have been missing."
"I personally had a completely different thermostat design on my car with the 2.0 CR engine (same engine code), because it was missing a 20mm bore since the thermostat was mounted externally."

So, things that you often only realize during a renovation...
Best regards.
Adrian.

"To my knowledge, the AVF engine is also installed longitudinally in the Passat. I'm not too worried about the mechanical aspects; the brackets and other components can be adapted. I bought the engine, and it will be installed/replaced this summer. My AVF has 520 injectors, while the one I bought is an earlier model with 550 injectors. I've read various things online, and based on this information, I plan to run the engine using my own ECU. The fuel injection volume due to the slightly larger injector will be a bit higher, which could potentially result in increased power, or otherwise just more smoke. I will definitely report on how the engine runs; if it doesn't run well, there are ECUs available for purchase in Poland without an immobilizer and with the correct part number."

tobias_ wrote:

My AVF has 520 PDEs, while the one I bought is still one of the early models with 550 PDEs.

The 550 injectors are of the PDE 1.3 generation, while the later 520 injectors used in the AVF engine are of the PDE 1.1 generation. They are not electrically compatible. The engine will run poorly if the type of PDE injector doesn't match the engine control unit. You need to make sure you have the correct ones. One way or another.
The 520 injectors do not inject a smaller amount of fuel in the case of an AVF engine.
The later versions of this engine focused more on finer atomization in relation to other emission values.

The AVF (presumably a type of engine or machine) also had various clutches and flywheels, depending on the specific model number.

Could you explain "electrically incompatible" in more detail? I've read about it before, but I've never found any specific details. As far as I know, both are PD elements with a magnetic coil, not piezo elements. Is the coil constructed differently, so that the control unit interprets the signal differently than expected?
That would be a shame, it runs so nicely with the chip .

I would also appreciate any recommendations for reputable chip tuners to whom I can send my engine control unit (ECU) and have it returned with good software installed.

Neither of those are piezo injectors. The 1.1 models were simply the next stage of development for that time. Among other things, they have different solenoid valves. They operate faster than the 1.3 models. This was important on the way to later engines with particulate filters, as it allowed for post-injection during the regeneration process.
You either need a motor control unit (ECU) that is compatible with the PDE engine type and can be programmed accordingly (including immobilizer and WFS pin), or you can have a tuner modify your existing ECU. Since you're already planning to increase performance anyway...

Okay, so it seems I can't avoid using another software.

"My engine has a friction-damped tensioner pulley installed, while the one I want to install is a hydraulically damped one. Does anyone know if I can reuse the timing belt components from my current setup, essentially converting it from friction-damped to hydraulic damping?"