ALH vs. AGR: Is ALH a AGR Replacement?

Basically, this question has already been discussed in this forum in a similar way. However, not in as much detail. Therefore, here's the question:

Can a faulty AGR (Abgasrückführung) be replaced with an ALH (another engine type), while keeping all the attached components, including the ESP (Abgas-Trennventil), turbocharger, and exhaust manifold?

Perhaps one of the experts here could answer the question with a simple 'yes' or 'no'?

Thank you very much and best regards,
Janosch.

No, that's not going to be that simple (unless you're just swapping the turbocharger unit without anything else, but don't quote me on that). The ALH engine has a VTG turbocharger, while the AGR turbocharger is equipped with a wastegate.

Best regards, WarLord.

Sure.

And because there are different chargers, there are also different control units and other valves. The EGR system probably doesn't have a vacuum reservoir either.
and so on... and so on.

m;

No, that won't be that easy (unless you're just swapping the turbocharger without anything else, but don't hold me to that). The ALH has a VTG turbocharger, while the AGR turbocharger is equipped with a wastegate.
Greetings, WarLord.
Yes, that's exactly what I mean. I just want to swap the engine block. Is that possible? Will the fuel injection pump and the EGR exhaust manifold fit the new ALH engine block?

Best regards,
Janosch.

Hello Janosch74!

I personally own an A3 with an AGR engine and a G4 with an ALH engine, so I am quite familiar with both engines.
If you are truly only transplanting the mechanical engine components of the ALH into an AGR (Exhaust Manifold with Turbo, Intake Manifold, Engine Control Unit, Mass Air Flow Sensor, etc.) environment, then I see no problems in 99% of cases.
The ALH block has a different part number than the AGR block, which I primarily attribute to potentially additional mounting threads for attachments (e.g., vacuum reservoirs). The internal components of the engines are identical, except for the pistons and the injectors. The pistons have a modified piston crown shape due to the Euro3 standard, and the injectors have an opening pressure of 220 bar (instead of 190 bar in the AGR).
However, this shouldn't cause any problems. You should simply check the pump timing.

Good luck with the renovation!

Regards,
Alex.