Radiator replacement
i have 2012 w212 E550 with Vin: WDDHF9BB2CA612581, my radiator have leaked so have to replaced it.
i went to online fcpeuro and they are selling the 3603, i went to dealership and rhey also selling the 3603 (20450003603).
so i went ahead and bought the parts. After receiving them and comparing the old ones i have, the 3603 have ports for transmission cooler lines and the one i have is 3703 which do not have transmission oil cooler lines.
i called nearest benz parts dealership and they confirmed thru vin that 3603 is the correct part.
the old part that busted is 204 500 037 03
any advise would be appreciated.
Old part: 20450003703 without transmission oil cooler lines
New part: 20450003603 with transmission oil cooler lines




You've got a replacement with optional tranny lines... to be unused on your chassis.
No problem, your option is safer againt mayo mixing.
Same everything else is ok
Last edited by CaliBenzDriver; Dec 15, 2024 at 02:21 PM.
New part3603: port blocked by aluminum if any water coolant flowing it becomes an orifice that control the flow.
can you also please run if you have or anyone? Now in case mercedes benz tech says it is ok, hlw does tha port blocking aluminum affect the cooling system overall? Or it is alright! Anyone have cross same issue as mine?
appreciated anyones input.
thanks & Regards,
after going back and forth and searching online. The part number 3703 was available in europe. Instead of ordering the exact part number that came with my vehicle i just used the 3603. I filled up the reservoir with G48 and voila the coolant just make its way. Ive used 3 gallons for now and it is right on the mark in the resevoir.
in summary, for any user end up having same case as mine when they replaced their 3703 with 3603, does it work? Yes.
i bought mine as used so cant really verify what happened if it came with original part number 3703 from europe or during that period someone just bought online and replaced it with 3703 instead of using the 3603 which is the right part number and shown as well in the EPC program.
thanks again and now i put them all together just need to call mobile car guy to vacuum and recharged my AC as it neeeded to be removed to really remove the radiator. Mine is pre face lift 2012 w212 E550 for everyone’s information.





