Reviews of Nissens heater core

I too have a 12 Jetta GLI, and bought a Nissens Heater Core from rock auto and was unable to close metal clips onto the new heater core. I had no trouble closing it with the original heater core.

I then removed the existing heater core and replaced it with the new one (Nissens) and checked for leaks in the coolant system using my coolant vacuum. I had no pressure leak offs after 1hr., 15min. so I assumed since it was holding pressure there was no leaks.

After polling the audience, seems like Nissens is a reputable brand to go with. I wanted to try something different than OE since the OE doesn't have a good track record to begin with.

I went with the nissens heater core as opposed to OEM. The veins on the heater core are definitely bigger which may help prevent future clogs as well. Of course it's a snug fit for it as opposed to the OEM that slides in like butter. I tried blowing air through the clogged heater core and it was like breathing through a straw. The new one is wide open.

Nissen is a quality brand. They’re designed that way to produce optimum heat. I think it’ll be a long time before you have to deal with clogging again.