AHU vs. 1Z: What's the Difference?

Hello fellow diesel enthusiasts!

Unfortunately, I couldn't find the answer using the search function, so here is my question:

What is the difference between the two engines?

I used to have a Golf 3 (Mk3) from 1995 with a 1Z engine, and now I have one from 1997 with an AHU engine.
At first glance, the two machines appear very similar, differing only in their year of manufacture, and both are equipped with a VP37 pump.
But there must be some difference, otherwise they wouldn't be changing the MBK (Mercedes-Benz Key).

Thank you in advance for your clarification.


Best regards,

Hello on this beautiful Saturday!

Can anyone explain the differences to me?
The only thing I've found so far (although it only relates to chip tuning) is that KW Systems offers two different chips for the two engines.
Hab nochmal über meinen letzten Post nachgedacht von wegen 'subjektiv ging er besser' ist warscheinlich vollkommener Quatsch, er fuhr aber definitv 10km/h schneller im Topspeed (205) der AHU nur (wie es auch sein sollte) ca 190km/h...Drehzahlen weiss ich leider nicht mehr...Mein 1Z hatte einen VDO-Tacho, der AHU einen anderen! Dispersion?

Greetings from Capernaum.

Hello Capernaum,

As someone who also drives an AHU-engine car, I've been interested in this question for a while, but I haven't found much information on it yet. In Rainer's 'suggestion thread,' I already mentioned that the differences between engines are likely to be of interest more often (even for other engine combinations). The problem is, who has the knowledge and also the desire to write all of that down?

Regards,
-Private

There are blind plugs available for the side airbags in VW vehicles; ask your local Votex dealer for more information!

@kenny



Or am I blind?

@KombiBlue

KombiBlue wrote:

@kenny Or am I blind?

Read the signature of -Privat...

Quote:

Volkswagen Golf 3, AHU 66 kW TDI without modifications, 170,000 km, manufactured in 1997, with side airbags that I still want to disable in order to install Recaro seats.

@Bertil

I am blind!

As the saying goes: Those who can read have a clear advantage!

Okay, you're welcome!

@kenny:

Thank you for your answer and the private message response. I will inquire at a different Volkswagen facility than the one mentioned in the thread https://community.dieselschrauber.org/en/viewtopic.php?t=804&highlight=seitenairbag. Perhaps they will know more.

Regards,
-Private

Oh no, now Rainer has closed the thread. (which was understandable ).
However, I'm still curious about where the difference lies. The thing about emission standards doesn't quite add up either, because my colleague with the AHU engine in his Passat 3B also only has EURO 2 compliance...

I now know of a difference:

The AHU (Air Handling Unit) has the Flexroh-Kat combination from AFN, which means it includes a section with a long flexible duct and a truncated catalytic converter.

With a free-flowing exhaust system (like a 1Z), everything is unconstrained until the manifold, which means the entire exhaust system can vibrate excessively.

I also have photos - if anyone wants them.

Okay, please provide the German text you would like me to translate into English. I will only provide the translation.

Hello Dieselmartin!
If it's not too much trouble, I would probably be interested in seeing the photos.

Thank you very much in advance.

Greetings.

My car has a new flexible pipe and a new catalytic converter (the original part was like that from the factory).



An AFN with a support structure (the AHU I crawled under looked the same).

@dieselmartin:

Thank you for crawling!
Hmm, that's a strange thing, but you're right: the suspension on the AFN seems to be a bit more robust, and if the catalytic converter or the flexible pipe ever needs replacing, it can save money.

Best regards.

Hello,

Basically, there's no difference between the 1Z and AHU engines. Volkswagen simply ran out of engine number sequences. If they had used seven-digit numbers, all the AHU engines would still be designated as 1Z.
Nevertheless, one will naturally find differences because the AHU engines are newer than the 1Z engines, just as a 1Z engine from a 1990s Audi 80 is different from a 1Z engine from a 1996 Volkswagen Golf.
However, these differences cannot be determined solely by the license plate code; rather, they depend on the year of manufacture and the specific vehicle.

Hello.
Wolfgang.