Reviews of OEM Volkswagen heater core

The heater core in your GTi is basically a mini radiator attached to the coolant loop. When you turn the heat on your open the heater core to the current engine coolant, thus getting the coolant cooling power of your standard rad and your mini radiator attached deep in your dash/firewall area. This heat is then pumped into the cabin.

I think once your car develops a heater core issue, it’s time to sell it. Taking out the dash and redoing your entire A/C system afterwards is enough of a big job for me to comfortably say your car has reached it’s road life and it’s time to sell. The heater core was and is still the biggest nightmare job you could ever have to do on a TDI, unless it’s a newer model of the last 10-15 years. Use the Purple pink coolant always. Yes the job is extremely complicated if you have to rip the entire dash out. Heater core are problems with all VW’s.

Finished the flushing of the coolant system 3 times today then replaced the heater core. Refilled with VW G13 coolant, burped the system, ran it up to operating temperature and voilà, consistent heat once again.

I just had the same symptoms and it was the heater core. 2014 Jetta SE 1.8 TSI with 54K miles. I hope that isn't it for your sake.

Quick update: 12/29/18 Ended up taking apart the heater box and fixing the vents and their pesky foam, and also replacing the old heater core which looked like it was original factory.

Bought a OEM vw core. Not taking a chance on jobber. Seeing I didd the labor myself the job only costed me 160$

My heat was getting weak again,so I just did another flush with HOT vinegar water mix 50/50. blow out with a bit of low pressure compressed air, flush again with the same solution, reheated again. Lots of gunk came out. Heat is good again.

Update: After several days with my newly flushed heater core, the heat output is amazing. Almost too hot at times! I have never experienced such hot air before on any vehicle I have driven.

Uh oh, an antifreeze odor coming from under the dash is usually a heater core leak.

It's fixed I have heat thanks to all yous, I flushed the heater core both ways low and behold I have heat.