Low coolant 2021 CX-5 GT

[georgist]

Hi,
bought a mazda cx-5 2021 GT, notice now it has coolant below the "L" level, had not noticed this when I bought it, so either it's leaking or was (more likely) low at purchase.
It *looks* like FL-22 as it's bright green.
Should I get FL-22 or close equivalent and top it up or do a flush and refill?

I wonder if I'm forced to flush either way as if I use OEM FL22 the previous owner *could* have used non-mazda coolant that is green, and in topping up with real FL22 I'm mixing. Or if it's the original coolant I can't buy non-mazda as that's mixing. Catch 22.

Another alternative would be to delay the flush by topping up with distilled water.

Any advice please?

edit: low mileage 21k!

 

[paris1]

You're overthinking this. Just top it off with distilled water. All Mazdas boil off a bit of coolant and require topping off every now and then. And yes, FL22 is green.

 

[Kedis82ZE8]

I just used Zerex Asian Coolant when I changed mine in early ‘23 so color won’t be a good indicator of stock fluid

Green coolant?

Mazda changed to the 55/45 mix a few years ago because of an issue with heater cores rusting How does an aluminum heater core 'rust'? And even if it did, I can't see how reducing the water content from 50% to 45% would stop any corrosion. On a serious note, where did you come across this...

mazdas247.com

I plan to follow Mazda schedule of simple drain and fill at 2 year intervals with the non-FL22

https://www.mazdausa.com/siteassets/pdf/owners-optimized/2015/cx5/2015-cx-5-maintenance-schedule.pdf

A lot of my maintenance is drain and walk away… use other vehicle if needed…come back later to fill….not a big deal

 

[MichalP]

There should be a label on the cap of the reservoir specifying which coolant you should use. Both my Mazda 3 and cx5 were slowly loosing some coolant initially and once it started getting closer to low level line I asked dealer to top it up and that's it. After first top up the level remained the same for several years. Now my CX9 was doing the same thing and approx after 1.5 years had to top it up.

 

[Kedis82ZE8]

Just my experience…only times I have lost fluid in my coolant recovery tank in any vehicle the last 20-30 years was either caused by a water pump leak or a bad seal on the recovery bottle that allowed for evaporation.

Other than that.. it would take several years to evap off the coolant bottle in vehicles I have owned to any noticeable amount

 

[LeSheep]

Mine reached the L after about 3 years 60k km. Topped up and so far all good

 

[yrwei52]

Hi,
bought a mazda cx-5 2021 GT, notice now it has coolant below the "L" level, had not noticed this when I bought it, so either it's leaking or was (more likely) low at purchase.
It *looks* like FL-22 as it's bright green.
Should I get FL-22 or close equivalent and top it up or do a flush and refill?

I wonder if I'm forced to flush either way as if I use OEM FL22 the previous owner *could* have used non-mazda coolant that is green, and in topping up with real FL22 I'm mixing. Or if it's the original coolant I can't buy non-mazda as that's mixing. Catch 22.

Another alternative would be to delay the flush by topping up with distilled water.

Any advice please?

edit: low mileage 21k!

Your 2021 CX-5 GT with 21K miles most likely still has factory coolant. Go get a gallon of Mazda OEM pre-mixed 55/45 FL-22 coolant for MSRP $25.32 and top it off to the “F” mark. Mazda has changed the formulation on its coolant with stronger 55/45 FL-22 content since 2020 MY CX-5 to fight against rust issue in cooling system which potentially could clog the heater core. You don’t want to add distill water to further dilute the FL-22 coolant from factory.

TSB No.: 07-007/19 Poor Heater Performance and/or DTC P011A:00 Stored

 

[yrwei52]

There should be a label on the cap of the reservoir specifying which coolant you should use.

Yes, FL-22 coolant that it is for Mazda. IMO the only exception is you flush the entire cooling system clean (unfortunately it isn’t easy for Mazda as there’s no drain plug on cylinder block) and use a different type of coolant which at least is aluminum friendly. I personally would always use the same type of coolant factory specifies. I never like the idea of mixing different types of fluid together.

Both my Mazda 3 and cx5 were slowly loosing some coolant initially and once it started getting closer to low level line I asked dealer to top it up and that's it. After first top up the level remained the same for several years. Now my CX9 was doing the same thing and approx after 1.5 years had to top it up.

I have similar observation on coolant level behavior from my 2016 CX-5. The coolant level was low during the new car inspection and I stopped the tech trying to use tap water to top off. I did ask a service advisor I familiar with to top off and he guaranteed he’d use FL-22. The SA did the top off another time during the warranty visit and the coolant level seems to be stabilized at the “F” mark eventually afterwards. I checked the water pump and several areas and couldn’t find any trace of coolant leaks. My theory is there’re some air pockets in cooling system from factory. They escaped from the system after many miles of driving, hence the coolant level dropped and needed top off.

 

[yrwei52]

Just my experience…only times I have lost fluid in my coolant recovery tank in any vehicle the last 20-30 years was either caused by a water pump leak or a bad seal on the recovery bottle that allowed for evaporation.

Other than that.. it would take several years to evap off the coolant bottle in vehicles I have owned to any noticeable amount

Yes, this’s my experience too. The dropping of the coolant level on my 2016 CX-5 when new is the first vehicle I’ve owned having such issue. I was concerned initially after saw a TSB of water pump leak. I checked water pump and several areas at the time and couldn’t find any leaks. The coolant level eventually is stabilized and I blame the issue on air pockets in cooling system from factory.

 

[Lazy2.5]

There are no leaks. These cars are known to consume some coolant, presumably in the combustion chamber. They can reseal themselves over time and stop/slow down consumption.

Using some green asian car blend really shouldn't be any issue, but use FL-22 and/or distilled water if you can.

 

[Kedis82ZE8]

I'm open to hearing new things but never heard of any amount of coolant making it past the head gasket into the combustion chamber as being a good thing. Also never heard of one resealing itself. Or is the coolant making it's way into combustion chamber from some other area of engine?

 

[Lazy2.5]

I'm open to hearing new things but never heard of any amount of coolant making it past the head gasket into the combustion chamber as being a good thing. Also never heard of one resealing itself. Or is the coolant making it's way into combustion chamber from some other area of engine?

Never said it's a good thing, but then again, I don't think we're talking about enough consumption for it to be a concern.

Someone mentioned here that their car used to do it, then stopped. I encountered the same thing.