Hello.
I'm hoping that someone would be kind enough and maybe shed some lights.
I finally had to bite the bullet and replace the heater core on my 91 190E 2.6 baby.
Using the awesome "How to" from Pelican + lots of cussing

i was able to get it it in the end.
Took the replacement Nissen 72002 out of the box and proceed to put it back in the box and this is where i got stumped.
The original core (a Behr going by the inscription on the side) has 2 openings with 2 holes per each opening. The replacement core has 2 openings with 2 holes per each opening as well BUT one of the openings has, what appears to be, a plastic tube connecting the 2 inside holes.
Now is that plastic tube some sort of "guarantee" that the part is brand one and i need to pull it out or somehow did i end up with a wrong part, even though it just like the original ?
I attached 2 pics of the replacement core which shows the 2 openings. Thank you