Mazda 3 coolant top up

dbest, Oct 7, 12:52am
Hi All,

I have a 2009 Mazda 3 with about 75k kms on the clock.

I noticed the other day when doing routine oil level check that the coolant level has dipped a little bit under the MIN mark. I don't think there is a leak or problem, probably just some evaporation over time.

I am wondering is it okay just to top up with some premade coolant or should I drain and refill ?

franc123, Oct 7, 1:01am
Have you got any idea how long it may have been in there for? If theres no service record for a change or a sticker under the bonnet saying it has been then chances are it's original and should be flushed and renewed. I would assume that car would have had a long life coolant in it but that generally means it has a 6-10 year life.

marte, Oct 7, 1:42am
#2 I agree, coolant goes bad, that's how it works. It sacrifices itself for the sake of the engine components.
Flush a couple of times with distilled water & refill with the same coolant.

If you are going to a more updated coolant, flush a couple of times with rain water, or tap water, then use a coolant flush product IF the manufacturer says you can use it, use the correct one.
Then flush again, & twice with distilled & then fill with new coolant & distilled.

gazzat22, Oct 7, 9:23am
From what I,ve heard and read the coolant dilutes with age and use and the test that garages/agents do is for the concentration.

kazbanz, Oct 7, 9:56am
As a here/now I would fill up with coolant the same color as is in there.
but well worth doing a coolant change and documenting date/miles

intrade, Oct 7, 10:49am
you need the correct coolant depending if it is actuarly a ford or a mazda engine correct factory spec coolent muste be used it can be mesured with a refractometer and with a multimeter for electrolysis. if ok can be topped up with exactly what was in there . NORTHING ELSE!

dbest, Nov 9, 4:52pm
I am pretty sure that coolant is original to the car. I think I will get it flushed and replaced to be safe.