Mazda 6 Forums banner

Engine Coolant

10K views 4 replies 5 participants last post by  Cdn17Sport6MT 
#1 ·
My vehicle is a 2018 Mazda 6 2.5T Grand Touring Reserve.. owned it for 1.5 years & current mileage is 26,000... Usually every 5,000 miles I get the vehicle serviced at my local Mazda serviced using 5W-30 Full Synthetic Oil.. Today I noticed my engine coolant was near the L mark.... Seems pretty low since I have just under 30,000 miles.. for our cars (2.5T) Mazda recommends: Mazda Coolant FL22.. Do i need a full-flush done soon at the local Mazda dealer? or add FL 22 Mazda coolant? Accoring to our service manual for the 2.5T on page 6-27 "add enough coolant to the coolant reservoir"


 

Attachments

See less See more
1
#2 ·
My vehicle is a 2018 Mazda 6 2.5T Grand Touring Reserve.. owned it for 1.5 years & current mileage is 26,000... Usually every 5,000 miles I get the vehicle serviced at my local Mazda serviced using 5W-30 Full Synthetic Oil.. Today I noticed my engine coolant was near the L mark.... Seems pretty low since I have just under 30,000 miles.. for our cars (2.5T) Mazda recommends: Mazda Coolant FL22.. Do i need a full-flush done soon at the local Mazda dealer? or add FL 22 Mazda coolant? Accoring to our service manual for the 2.5T on page 6-27 "add enough coolant to the coolant reservoir"
Mazda recommends:
Replace at first 192,000 km (120,000 miles) or 10 years; after that, every 96,000 km (60,000 miles) or 5 years.

I would probably just add mixed FL-22 to top it off.
 
#3 ·
Add some FL-22, then keep an eye on it.

It's not unusual to lose a little coolant during the summer months, especially with a turbo.
 
#4 ·
Mine was delivered with a full radiator and zero in the overflow bottle. It has never consumed any.

The cooling system is supposed to be sealed EXCEPT that if the radiator is completely full then since the coolant expands it is forced out through the cap into the "overflow" bottle. When it cools that coolant is sucked back in since there is now negative pressure.. The level should change in the overflow bottle IF there is some in there and there is ZERO air space in the radiator, due to expansion and contraction with heat, but no more and cold level should be cold level, period. In other words if you have coolant in the overflow bottle there should be ZERO airspace in the radiator and the cold level in the overflow should be the same for a given cold temperature (it may, obviously, drop a bit if it's REALLY cold -- e.g. in the dead of winter.)

If you're losing coolant then it's going somewhere. The "somewhere" can be external (bad) or internal (catastrophically bad.)

If your vehicle was delivered low then (1) check the level in the radiator (DO NOT remove the cap except with the engine DEAD COLD!), fill it ALL the way and then (2) fill the bottle so it's just above the "minimum" mark again, with the engine COMPLETELY COLD.

Then pay close attention to it. The level should NOT change when checked, again, completely cold. It will change a bit when warm.

BTW this is one of the things that the European makers (e.g. VW/Audi) tend to get right; their "expansion bottle" is where the pressure cap is, it's under pressure, it does NOT have free air communication and as a result the coolant in said engines tends not to deteriorate at all (and thus it requires a LOT less maintenance) provided you don't put anything that shouldn't go into the system in there.

Do not ever put anything except the proper coolant and DISTILLED water, in the proper proportion, into the system. This is especially important for engines that have aluminum components -- and SkyActiv does.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top