2004 B6 Audi S4 radiator ... time to replace

[justanothernoob]

I have the common radiator fault: seem at the driver's side top corner of the radiator has started to give and I now have a lovely fountain / water feature. Needless to say, this was not on my Mods list!
I might try some Knead It putty to see if that gives a temporary fix (it's worked wonders in the past when the top plastic hose connector broke) but probably need to accept that it's time to replace the radiator.

A genuine OEM from Germany is going to set me back NZ$1800 + GST + 4 hours' labour = 2,735 bucks!!!

Apparently there are different models between the manual and the auto / tiptronic but ...

I can have OEM from the US delivered for just under NZ$1300:
https://jhmotorsports.com/shop/catalog/radiator-main-oem-for-b6-s4-with-manual-or-automatic-transmission-p-1143.html
(part number 8E0 121 251 AB)

Or there are aftermarket replacements for around N Z$650 (delivered)
https://jhmotorsports.com/shop/catalog/radiator-main-oem-for-b6-b7-s4-with-automatic-transmission-p-1682.html
(part number 8E0 121 251 AJ)

I've been in touch with JHMotorsports and they've explained that there "might" be a difference between the US domestic market model and mine so they need me to confirm the part number before they can confirm if they can supply a direct match.

So I have the following questions:

1/ does anyone know where the part number is on the radiator - I can't see it without starting to take things apart but hopefully someone can talk me through how to find it
2/ is there any way to find out the correct OEM part number using my VIN number. I'm guessing there must be because the dealerships are able to quote me a price - but it wouldn't be fair to ask them for the part number and then buy elsewhere. And I'm not that cheeky!

Thanks in advance for all / any help.

cheers,

David

[00quattro00]

There is only 2 options, one for manual and one for auto. Auto one has a cooler in the end for trans fluid.

[justanothernoob]

Ya beauty!  So the JH Motorsports guys are sending me off on a red-herring re. possible regional differences?

I checked at partslink24.com and using my vin number it comes back with a heap of different radiator models:
8E0 121 251 x  where x could be:

A for "heavy duty water-cooling system"
P is for tiptronic
C, G and J are just "radiator"

Does anyone know how much of a difference there is between the models?

[00quattro00]

Those parts sites just look at the model code in the vin and then just list all the parts that apply to that. 8E0 121 251 xx is the part number for the radiator for the b6, the letters specify which exact application. There is only 2 options for the 4.2, manual or auto

[justanothernoob]

thanks.

So the AB version ("... with oil cooler") would be for the auto and the AC (just plain "radiator") would be for the manual?

Do you know what the other letters mean or why they exist? I did wonder if they were incremental to represent versions for slight changes in design (to fix known faults), manufacturer, etc., ...

Sorry to be pedantic - but once I order this from the US, the freight costs mean there's no returning it if it's the wrong one!

Cheers - really appreciate your help and advice 

[Worms]

VW/Audi part numbers often AREN'T incremental for updates, but sometimes are... no guarantees! It's pretty stupid.

[00quattro00]

So the AB version ("... with oil cooler") would be for the auto and the AC (just plain "radiator") would be for the manual?

Correct