New owner of MK 2 GTI here. Got excited and removed the lower parts of the dash and console to replace the heater core last week- went fine and only took about 4-5 hours all in with a thorough cleaning of all the parts.

Notes to all thinking about it- I used a new MK 3 heater core and while it does fit in the same position, it is not exactly the same as the original and the hoses will need to be attached further inside the firewall (just inside) rather than external to it. Also the sealing around the hoses will need to be addresed with some foam as the MK 3 surround and foam can not be readily used. You have been warned! I might post a picture up to explain.

Anyway I now have heat and it's all good.

Next problem- the heater hose from the cylinder head to the heater is torn / split and taped up while I scratch my head on replacing it as my car is an automatic and the hose branches off unlike the manual version which is just a straight through hose. As the hose is 90 pounds to buy out of the UK. (VW were useless here and didn't want to assist), I am wondering if i can change the hose outlet on the cylinder head to one that splits the coolant thus enabling me to plumb to the heater like a manual version and use another port from the hose outlet to plumb off to what ever else is needing the coolant (I am assuming it's a trans cooler or similar).

Anyone done this before to an automatic MK 2? If I am correct and can use other non standard but original VW parts, it will be a load cheaper than the correct 3 way hose for the automatic.

Happy to hear from those that have done this.