2.0 TDI EA288 184 Timing Belt, Coolant flush & new Thermostat

SuperV8

Active Member
May 30, 2019
1,545
685
Finally received my new heater matrix - even just blowing through it you could tell the old one was restricted.
Thought I would do a simple hose test of old and new and you could also see a difference in flow.

OLD vs NEW
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when I fitted it I started the engine to circulate the coolant and check I had no leaks, all was fine. BUT I noticed when I switched my engine off only after 5 mins of idling I could just hear the small electric pump pumping coolant through the micro circuit of the heater matrix and EGR cooler - flowing coolant through the heater matrix, with a partially restricted heater matrix this small electric pump will struggle to flow coolant arround this micro circuit and its easy to think after a DPF regen there will be a lot of heat in the EGR cooler that can't flow to the heater matrix and so locally boils and expels through the header tank cap!
I have noted previously after stopping after a drive that my main fans are on for a fair amount of time! Enough for me to think - wow my fans are still on (minutes later) - my theory that after a DPF regen and I stop - there will be a temperature sensor somewhere near the EGR cooler 'waiting' for the micro circuit to bring the temps down before it switches off? and with restricted heater matrix it can't or will take longer? Anyway i'll keep an ear out see if the improves?
 

SuperV8

Active Member
May 30, 2019
1,545
685
Another point I noticed was the price variation in heater matrix between the winter and summer!
when I last looked at getting a new heater matrix - would have been November time I could not find a single one for less than £90!
Now You can see the cheapest (aftermarket) one's around £25!
I'm sure this same but opposite for AC parts!