Golf GTI Mk7 heating slow to turn on

Hi guys,


My climate control in my 2015 Golf GTI Mk7 with ~100k miles on it is starting to behave. On my usual road to work, which mainly consists of B roads I don't get any heat into the cabin after 15 min. with the motor oil at ~90 degrees and the water is obviously at approximately the same at that point.


However, as soon as I rev the engine to 3.5-4k RPM the heat comes on, which makes me think that the turbo actually kick starts the heating somehow.


Do you have any clue what could be at fault here? A regular OBD scanner doesn't find anything.

Maybe check to see if the bag in the coolant broke if you have one? I've heard of them breaking in some cases and clogging the heater core

Can you elaborate on what you mean by "bag in the coolant broke"? Do you mean the coolant reservoir?

rfalc said:

Can you elaborate on what you mean by "bag in the coolant broke"? Do you mean the coolant reservoir?

Click to expand...

Here you go:
https://www.golfmk7.com/forums/showthread.php?t=49834&highlight=Coolant+bag

Interesting, I'll have to check it in day light over the weekend. However, it does seem weird that the heater core should be clogged, seeing that the heat actually does come on after the engine has been revved a bit.