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Water sloshing\moving through dash when first starting the CX-9

:
2016 Mazda CX-9 GT
Hello Everyone,
I've been reading and saw the issue with the ac drain line clogging, but the sound I hear is when I first start our 2016 CX-9. It sounds like water going through pipes. This happen before I turn the AC on and before driving. The noise comes from behind the dashboard, around the middle. Any ideas?
 
Yes be concerned and don't wait too long. It is a simple 3-5 minute fix if you do it before your fan motor ($40-70) and power resistor ($80-120+) get shorted. It is a problem with the drain from the rain gutter. It gets plugged up with debris and wont drain well and the water backs up until it gets in your front dash fan assembly (under/behind the glove box). When you turn you hear the sloshing, and if you have the fan going it really makes a weird noise. An early sign of this is the floor gets wet on passenger side after it rains

To fix put your front wheels on blocks or up on your curb to get more room under the car. Easier to let the car cool down some. about a foot or so behind the front wheels you can see the exhaust tube running down the middle of the car. There will be some aluminum mesh. Pull down the front driver side corner of the mesh away from the car. you will see a white exit tube. that is the drain plug. get your shop vac and put a reducer on it to get better suction on the drain. I used a piece of plastic tubing and some duct tape on the end of the wet vac hose. Make sure your face is not right under it or you WILL get wet. I have also used compressed air into the drain and it usually unclogs it but not as well. This happened to me two years ago. and I did not figure it out until the blower motor and fan resistor shorted. I ended up getting two of each. Let me know if your motor or resistor go out and I will give you a good deal! Here is a youtube link
 
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2016 Mazda CX-9 GT
Quick update. I went looking for the ac drain line on the 16 CX-9 and while I was looking, I saw that the coolant reservoir was under the Low mark. No leaks noticed anywhere near the water pump or broken hoses. Bought some FL-22 fluid at Mazda and maybe added about a 1 cup or 1 1/2 cup to the reservoir to bring it in between the low and full marks. Started the car up and no gurgling noises. Wonder if it was just low and getting air in the coolant lines like Silly Wabbit said above.
 
Strange that your coolant would be low without leaks. For good measure check this location as well to see if there are any leaks.

 

Natey

Swollen Member
Contributor
:
Mazda
A babbling brook behind the dash is always low coolant. Let the car cool off then start it up. Pop off the coolant cap and fill to the brim while the car runs.
Distilled water only! I use a 70%-30% water to coolant mix. (y)
 
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Mazda CX-9 Grand Touring 2016
I use a 70%-30% water to coolant mix.
70% water may not provide adequate anticorrosion capabilities. 70% antifreeze won't cool as well in very hot weather as a higher proportion of water. Water cools better than ethylene glycol. (Race engines use water plus additives for best cooling. Antifreeze is also too slick in case of a leak on the track. If I lived in Death Valley I'd use distilled water plus Red Line Water Wetter for the anti-corrosion, anti-foaming, and wetting benefits.) 70% antifreeze is good down to -84°F.

Generally the recommended proportions range from 60-40 to 40-60. Use 60% antifreeze in winters down to -62°F. 40% antifreeze is good down to -12°F and still provides adequate anticorrosion, antifoaming, and other necessary qualities. 50-50 is good down to -32°F.

I think all the pre-mixed coolants I've seen, including Mazda FL-22, are 50-50.
 
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2016 Mazda CX-9 GT
Thanks everyone for the responses. I did buy FL-22 from Mazda and like I said it was not that low. I see no leaks anywhere and I am not sure what level the reservoir was at before. I purchased the car new in 2016 and never checked the levels on the coolant before. So I will keep an eye on it and see if it starts dropping.
 
Just FYI. Keep a very close eye on it if you are still under warranty. If you detect even the slightest hint of a drop in the level that's a problem. If you have a problem, even a minor one, get it on the record while it's still covered.

Vehicles should not use any antifreeze in normal use. If you do have a leak that is so minor that it's not apparent a pressure test will be needed. If it's minor then a few minute test is insufficient and the pressure tester should be left on for a decent amount of time to verify that the antifreeze is not 'going someplace'.
 
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2016 Mazda CX-9 GT
Thanks Rowlands57. I just marked the tank with a permanent marker and will keep an eye on it. Unfortunately not under warranty, I am at 72,000 miles.
 

Natey

Swollen Member
Contributor
:
Mazda
70% water and 30% coolant has kept my twin turbo rotary powered RX-7 healthy since the 90's, Regular track days in the summertime California desert with no cooling (or corrosion) problems ever.

Just my personal experience from driving one of the most volatile cars on the road when it comes to overheating.
 
Thanks everyone for the responses. I did buy FL-22 from Mazda and like I said it was not that low. I see no leaks anywhere and I am not sure what level the reservoir was at before. I purchased the car new in 2016 and never checked the levels on the coolant before. So I will keep an eye on it and see if it starts dropping.
I also had that water sloshing noise when I first started the car and drove around. I thought it was related to the HVAC drain however recently I found I had coolant leak from my engine. Long story short, I had to get the entire engine replaced. Once I got the car back I noticed that I didn't hear the water sloshing sound. I think my engine was initially leaking coolant slowly and as the volume decreased I started to hear the sloshing sound. Once the engine was replaced and the coolant was filled the noise when away.
 
:
2016 Mazda CX-9 GT
Thanks mchu123. I have been following your post as well. Did you see any other signs of the leak other than the low coolant? I pulled the plastic protective cover under my 16 CX-9 and found no signs of leaks on the engine, water pump or on the plastic.
 
Thanks mchu123. I have been following your post as well. Did you see any other signs of the leak other than the low coolant? I pulled the plastic protective cover under my 16 CX-9 and found no signs of leaks on the engine, water pump or on the plastic.
To be honest I am not really a car guy, so I didn't really look too hard. The car felt fine and I had been hearing the sloshing noise for a while before I noticed the coolant leaking onto the ground. I couldn't really see anything leaking from the engine bay as it was more the posterior part of the engine.
 

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