Oil-Water Heat Exchanger Retrofit, MKB AGR

Hello everyone!

Recently, I noticed that the AHF and ASV engines (110 hp) have a different, larger oil-water heat exchanger compared to the AGR and ALH engines (90 hp). However, the filter flange appears to be the same.
I'm considering replacing the heat exchanger on my AGR (Abgasrückführung) system with a larger one from an AHF or ASV (engine types) during my next oil change. I'm hoping this will not only provide benefits during longer, full-throttle highway drives, but also, more importantly, a faster warm-up of the engine oil in the winter.
Normally, the water temperature rises much faster than the oil temperature. A larger heat exchanger could therefore preheat the oil more quickly. In the summer, this provides additional reserves under high engine load. This is something that might be worth considering for those with caravans, especially if they have a vehicle with a 90 horsepower engine (???).

What do you think about it?
Do you have any idea where we can find a heat exchanger at a reasonable price? The new part from VAG is ridiculously expensive!

Regards,
Alex.

Hello,

I can only recommend it, it works great. At the same time, I cleaned and thoroughly flushed the cooling system. However, I only managed to get the expansion tank reasonably clear after two cycles in the dishwasher. I'm now using a mixture of 50% G12+ (BASF G30) and 50% distilled water. Fight the limescale! The old water/oil heat exchanger was already heavily encrusted with limescale. The result is now a faster warm-up and reaching the operating temperature, which is noticeable even with the better heating performance in this cold weather. However, the comparison to the oil temperature is still missing and will be added later.
I also only sourced those parts (expensively) from VW, but occasionally you can find similar items for sale on eBay.

Sepp.

Hello!

It's generally a good idea. However, try just changing the coolant first. I did the same thing with my ALH engine after 3 years, and I noticed that the engine warmed up a bit faster, and the oil temperature under load didn't exceed 110°C. Before that, it sometimes reached up to 118°C.

edit/
Manual switches with the standard SH (glow plug control) no longer have an electric pre-heater. Instead, the SH is simply switched on or off (under the same switching conditions) as with glow plug heaters.

@ Julian:
Hi Julian, what plausible explanation could there be for the fact that a coolant change leads to faster engine warm-up? After all, the amount of heat generated by the engine is the crucial factor. According to your theory, the specific heat capacity of the coolant would have to increase so much due to chemical changes that it would be noticeable during the engine's warm-up phase. I can't really imagine that.
Or did you mean something different, or am I completely misunderstanding, or...?
Please explain it to me!

@all:
I saw an offer for an oil-water heat exchanger with the part number 028 117 021 E. It is supposedly compatible with the AVM industrial engine. I also found out that it fits the 2.3-liter gasoline engine as well.

But does it also fit in the AGR (automatic gearbox), and does it, above all, have a larger surface area than the standard heat exchanger with the part number 068 117 021 B?

Oh, and then there are also some heat exchangers with the numbers 038 117 021 X, etc.

Could someone please explain this to me, or provide a chronological order from smallest to largest surface area, so I can make sense of all this information?

Thank you for your help.

Regards,
Alex.