I had a new radiator fitted under warranty to our MY02 WRX a couple of days ago as it was seeping coolant from the crimps of the end cap.

Since I got the car back I noticed that fron idle if the engine is revved slightly you can hear the sound of running water/gurgling from behind the left side of the dash.
I initially thought a pipe had been left off but there is not a leak to be found and he coolant level has not changed, I also noticed when I picked the car up the heater was set to cold. From my days of R5 GT ownership I remember you had to have the heater on hot when refilling/bleeding the system to include the heater matrix.

Spoke to the dealer who suggested it is probably an air lock which I am guesing is in the heater matrix.
Anyway the dealer said it should hopefully work its way through in a few days but if not they will bleed the system.
I am a bit dubious of this and a bit concerned of the implications of running the car with the air lock present in the system.

Any thoughts or similar experiences?

 

Dont worry about it mate,yes your heater wont be as effective until its bled but the engine should be fine.The heater unit is the highest point of the system so the air will go there, not the engine.

Zippy

 

Thanks for that

Stephen

 

I hear the same gurgling/bubbling sound every now and then, usually from the centre air vents. If I lightly blip the throttle, it bubbles a bit faster, so I assumed it was coolant (the water pump speed is controlled by engine revs, right?). I've tried bleeding air from the system by running the car up to temperature with the radiator cap off (stationary, not driving!) but no luck.

It isn't a problem - no leaks, heater still blows hot, no temperature issues - so I've just been ignoring it.