wrx_moto

Just recently I've started getting a strange sound of what sounds like running water. Seems to occur mainly when I blip the throttle at either stand-still or low speeds. It sounds exactly like running water i.e. not something more viscous like oil and seems to originate from the passenger footwell area (or as best I can tell).

I thought originally it was a problem with the heater matrix but now I'm not so sure. For one thing the heater is working just fine and there does seem to be this correlation between touching the accelerator and the noise ocurring. Everything else on the car appears to be working fine as far as I can tell. It's got me baffled and it's driving me nuts!

Oh and it's an 04 WRX with no engine mods.

Anyone any ideas?

Mother Theresa

A couple of us have had this and mine was fixed by a track-day. Probably an air lock somewhere.

Go for a burn and see if it fixes it.

(Even if it doesn't you'll have had a good time....)

wrx_moto

An airlock defintely makes sense but I'd have to say that it's already done about 1000 miles of fairly rapid driving, since the problem first appeared and if anything it seems to be getting worse rather than better.

Phildodd06

Yep sounds like an air lock, the sound you can hear is the water and air together.
On my RS2000, this was a commen problem, the fix was to blead the system, start up the engine with the coolant cap off turn the heaters on hot and full, then let it idle upto the fan twice, this should get rid of the air.
If it doesnt, thn another way was after driving, park facing upwards a hill and slowly open the coolant lip slowly just enough for the air to escape.
Not sure if it would work on the impreza's tho....

Mother Theresa

I suspect it was the harsh cornering rather than the engine speed that fixed it. Go out and try harder..