Hey Guys....

when I'm sitting in the car at idle and slowly press on the accelerator (up to about 2k rpm) I hear this splashing sound that sort of reminds me of water running half full through a pipe. It's not too loud but it almost sounds like it's coming from behind the dash. Anyone have any idea what this is?

S_D

Yes.

That is air in heater core. When you gently press the accelerator it "whooshes" the bubbles through it. The design of our coolant system is such that an annoying air pocket from Hiroshima lives in the coolant plumbing.

I noticed this from day one. I had a mechanic look at this and he said that placing the car on a steep incline (nose up)....and running the engine with the coolant resevoir cap off, will help air escape. Bringing the revs up and down will help push air bubbles around and hopefully into the resevoir.

I did this will him ......and the next day I started my car...the low coolant level light was on. It was low only by a tiny bit, so I added less than a pint of poland springs. Obviously we were able to burp out some air that was displacing the coolant and lowering the overall level a small amount.

BTW....carefull taking the resevoir cap off on a warm engine. Turn it half way with a rag over it and release air pressure first.

And I thought I was hearing things...
This car is really quirkey........that is why I love it

It's not just the 8 it happens to all cars. sometihes if you can loosen a hose clamp you can also get the air to escape. Just like purging the air from your plumbing after doing repair work. Just let the fluid flow and crack a fitting untill all the air escapes.

Taking the radiator cap off (not the coolant reservor), and placing a cut-off plastic pet-bottle full of water in there often does the trick. You cut the base off the pet-bottle and stuff the neck into the radiator, then fill up the pet bottle. This effectively raises the water level in the cooling system to well above the engine, which prevents air becoming trapped in pockets etc. Then you carry out the air bleed procedure in the Workshop manual (5 minutes at 4,000 rpm I think, but ASK YOUR WORKSHOP) to bleed out the air. Top up the reservoir tank if necessary and Bob's your uncle! This is not a registered rotary procedure, but works on any car that is difficult to bleed. Cheers.

good advice! now who is this Bob character i keep hearing about?

Tried the cap off parked on a hill trick. Level didn't change much at all. Worked for two days, now the noise is back. Any other ideas?

Although my coolant level did drop after purging air out of the system, I do hear the sound. Not as often as before though.

If your getting good heat, than the sound represents as a nusance only.....

Judging from the amount of people who mentioned hearing this sound, it looks like its here to stay.

I am going to try a steeper hill, and longer duration of 3 4k revs. If that doesnt do it.....I'll live with it:)

I've tried burpung the hoses, parking on an incline and purging and sacrificing a chicken. Nothing is stopping the noise.
When I first heard it, I thought I had water in the A/C condensation lines.
Of course, I have yet to use my A/C...

Originally posted by MazdaManiac
I've tried burpung the hoses, parking on an incline and purging and sacrificing a chicken.
Maybe try a goat.:D

I guess most of us have it - mine does too, but I don't worry about it.

Hey! I thought I was hearing things. I was kinda scared coz I thought it was the brakes. I was wondering why the brakes would make these noises while I'm running 80 mph! Yikes!

Now I know I should not worry about it :)

Well...tried all the suggestions and it's still hiding in there somewhere. Although as I've put mileage on the car I've noticed it seems to happen less often. (6.5k miles). Thanx for the help though! Guess I'll just live with it when it does happen.

is it just me or does anybody else think it sounds pretty cool..

dunno, I kinda like the fact that something is living inside my engine :P

I always thought it was from the petrol rushing its way to the engine...

Originally posted by Squidward
is it just me or does anybody else think it sounds pretty cool..

dunno, I kinda like the fact that something is living inside my engine :P

:cool:

well, i definitly have this too--- but is it really a problem?????

Originally posted by TPNova1
well, i definitly have this too--- but is it really a problem?????

Nope :)

Mine eventually went away on it's own about a month ago. Go figure.

just got my car back from the dealer. sound is gone. they bled it and filled it up for me. no more sound. im a happy man.

Bled what? filled what? Mine sounds like someone poured a bucket of water inside my dash.

Bled what? filled what? Mine sounds like someone poured a bucket of water inside my dash.

Bled and refilled the cooling system (antifreeze) I'd imagine.

rx8cited

Took mine to the dealer for the same problem and they said they couldn't get it to make the sound so they didn't do anything to it. (They had it for two days) And their solution was to oil my throttle...silly service people. So I guess I'm just going to ignore it since it dosen't really hurt anything.