[johnbruce]

I've just replaced the oil cooler on my 2002 Passat. managed to eventually get the heater matrix bled but can only get any heat when the temperature guage goes to almost 100 deg.C. Is this going to be a gradual process of the oil breaking down & clearing the heater matrix or is there a faster way. I've used 2 bottles of Wynn's rad flush but it is very slow

 

[Vent5]

Is the heater matrix another name for the heater core? The heat exchanger for the cabin right? Are you sure you bled all the air out? There's a hose that you pull half way off. There should be a writeup in the FAQ section. If you're not getting heat it's either air or buildup clogging it. You could try hot water and blasting one of the hoses with compressed air to blow out any buildup out the other hose.

 

[Stefan2006]

Are you using VW's G12 coolant or green coolant? You're splitting it 50-50 with distilled water right and not just coolant?

 

[johnbruce]

Thank you for the suggestions & possible answers.
I had bled the heater properly & was getting water back through the bleed hole but apparently the easiest way to get rid of the oil from the radiator & heater is to use a capful of BIOLOGICAL washing powder which I have now tried & the results have been spectacular. The overheating has almost stopped and I reckon 1 more flush with the washing powder and then a final flush with water for a couple of weeks before finally draining & filling with anti-freeze