strange water swishing sound in my m35 2006

[sfreedman]

Anybody have any clue what this could be?

often when starting my car and when accelerating from 0 to about 8 MPH, i am hearing on the drivers side what appears to be a sound of water swooshing around that seems to be coming from the area above the a/c vent on drivers side. the sound seems to go away once i get over 8 or so MPH or maybe i cant hear it over the engine noise. Any advice on possible causes would be appreciated. Dealer said to check the coolant fluids to make sure they are full and i did that already with no luck.

[maxnix]

Does your AC evaporator closet drain?

[mmm..good]

I've got the same issue on my '06 M35 X. Only had the car for about 3mos. Has 23K on it and just noticed it iver the past few weeks.

[SteveTheTech]

Hey there and welcome to Nico! How many miles do you have on your M?

What I am thinking is that you may have either air in you heater core and if that is not the case than you may actually be hearing the water rush through the veins of the heater core itself.

Have you have the coolant flushed recently?

[mmm..good]

Would the heater core need to be flushed after only 23k?

[exbmwdude]

Get it to the dealer ASAP - could be an air bubble in your cooling system. I had that problem when I first got my M too and if left unchecked it can sometimes cause overheating issues.

exbmwdude2006 M35S

[sfreedman]

Thanks for the replies.. The car has only 17k miles on it. I am original owner and it will be 3 years old in January (2006 model)i have never had the coolant flushed...

not sure what you mean by the question "does you AC evaporator closet drain?" do you mean do i see a puddle of water under the car after running the AC? if so, i have not noticed a puddle/drip lately but have also not looked for it. I will have to look for that..

per steve the tech's reply "you may actually be hearing the water rush through the veins of the heater core itself" if so, IS THIS FIXABLE?

[exbmwdude]

Yes it's fixable and you're hearing it because there's air in there with the water. Hit the dealer ASAP.....

[maxnix]

Would the heater core need to be flushed after only 23k?

The coolant should be replaced every 2 yrs. or 24K miles, if you own the car.

Distilled water is the best coolant dilutant.

[sfreedman]

is this considered warranty work?

[Nismodood]

if the coolant has been changed or maybe the vehicle was wrecked in the front and the radiator was replaced, it could have air in it. ive seen some people hit the shifter in manual mode and drive around in like 2nd gear on the freeway, not knowingly, and it overheated. then causing air to get in the system. the G's and FX's all encounter this same scenario so its not exclusive to the M's. Mostly with the VQ. bleeding out the air will solve the problem.

[sfreedman]

is this considered warranty work?

[SteveTheTech]

If your car is still covered under warranty that is a concern that should be handled without issue.