Block Drain on 2.5L

Wanting to do a coolant change.
Location of Block Drain plug and can I reach it?
Other plan-
Remove thermostat and leave radiator drain open while idleing the vehicle with garden hose in. Let it drain and fill with distilled water and drain 4 or 5 times. this will leave it with mostly nothing but distilled water in the block then fill up with concentrate.
So the question becomes if you simply drain the system at the radiator what percentage of the entire system is drained? If I were to have the block fill of disitlled water then topped off with straight AF what would my ratio end up being?

Considering this fluid in full strength
RAVENOL J4D2092 Coolant Antifreeze - HJC Hybrid Japanese Coolant Protect FL22 Concentrate (5 Liter)
https://www.amazon.com/dp/ (commissions earned)

Any other fully compatable FL-22 coolant that can be recommended?
Is there a previpous thread on full coolant flush change on the 2.5L? I find the search function to be smarter than me. Can't seem to narrow down the results.
 
I spose I could drain what I can from the radiator and see what the measured amount is. Looks like I would like to be able to drain half the stated system capacity of 4 quarts or so. My plan is to flush the sytem with tap water from the hose at an idle with the T-stat out running a garden hose running into the fill cap with drain plug out. Follow up with 4 or 5 fill, idle, drain of distilled water, and then add the correct amount of straight AF to bring me to a 50/50 mix. It will be a math project, hmm if a train left Chicago at 50mph and another left New York....
 
Wanting to do a coolant change.
Location of Block Drain plug and can I reach it?
Other plan-
Remove thermostat and leave radiator drain open while idleing the vehicle with garden hose in. Let it drain and fill with distilled water and drain 4 or 5 times. this will leave it with mostly nothing but distilled water in the block then fill up with concentrate.
So the question becomes if you simply drain the system at the radiator what percentage of the entire system is drained? If I were to have the block fill of disitlled water then topped off with straight AF what would my ratio end up being?

Considering this fluid in full strength
RAVENOL J4D2092 Coolant Antifreeze - HJC Hybrid Japanese Coolant Protect FL22 Concentrate (5 Liter)
https://www.amazon.com/dp/ (commissions earned)

Any other fully compatable FL-22 coolant that can be recommended?
Is there a previpous thread on full coolant flush change on the 2.5L? I find the search function to be smarter than me. Can't seem to narrow down the results.
Based on Mazda CX-5 Service Manual, there's no drain plug on engine block like many others. Any kind of flush is the only way to replace the engine coolant like the Step 4 stated. I wouldn't bother to remove the thermostat, but just let the engine idling and heater is at maximum with garden hose in and radiator drain on like you mentioned.

I definitely would use Mazda genuine FL22 coolant.

Mazda CX-5 Service Manual said:
ENGINE COOLANT REPLACEMENT [SKYACTIV-G 2.0, SKYACTIV-G 2.5]

NOTE:
● If the FL22 mark is shown on or near the cooling system cap, use Mazda Genuine FL22 engine coolant.
● FL22 type engine coolant is shipped as a diluted solution. Use the solution as is when replacing coolant.

1. Remove the cooling system cap.
2. Remove the service hole cover (installed to front under cover No.1) used to drain the engine coolant.
3. Loosen the radiator drain plug and drain the engine coolant into a container.
4. Flush the cooling system with water until all traces of color are gone.
5. Let the system drain completely.
6. Tighten the radiator drain plug.
7. Referring to the following chart, select the correct volume percentage of the water and engine coolant. Antifreeze solution mixture percentage (Except FL22 type engine coolant)
8. Refill the engine coolant from the radiator filler neck until it is close to the top of the radiator filler neck.
9. Refill the engine coolant into the coolant reserve tank up to the F mark on the tank.
10. Install the cooling system cap.
CAUTION:
● If the high engine coolant temperature warning light flashes, stop the engine to lower the engine coolant temperature and prevent overheating. Then, verify the malfunctioning part and repair or replace it.
11. Start the engine and warm up the engine by idling.
12. After the engine warms up, perform the following steps. At this time, be careful of the engine coolant temperature to prevent overheating.
NOTE:
● If the accelerator pedal is depressed continuously for a specified time, the engine speed may decrease to the idle speed. This is due to the fuel cut control operation, which prevents overheating, and it does not indicate a malfunction.
a. Run the engine at 2,500 rpm for 5 min.
b. Maintain the engine speed at 3,000 rpm for 5 s, and then idle.
c. Repeat Steps (1), (2) several times.
13. Stop the engine, and inspect the engine coolant level after the engine coolant temperature decreases. If it is low, repeat Steps 812.
14. Inspect for engine coolant leakage. (See ENGINE COOLANT LEAKAGE INSPECTION [SKYACTIV-G 2.0, SKYACTIV-G 2.5].)
15. Install the service hole cover.
 
Based on Mazda CX-5 Service Manual, there's no drain plug on engine block like many others. Any kind of flush is the only way to replace the engine coolant like the Step 4 stated. I wouldn't bother to remove the thermostat, but just let the engine idling and heater is at maximum with garden hose in and radiator drain on like you mentioned.

I definitely would use Mazda genuine FL22 coolant.

Question regarding the instructions at step 12c. Repeat step 1, 2 several times...the heck does that mean?

Question regarding step 13. If low repeat Steps 8-12....will it be safe to open the radiator cap? Can't I just fill the reserve tank instead?

12. After the engine warms up, perform the following steps. At this time, be careful of the engine coolant temperature to prevent overheating.
NOTE:
* If the accelerator pedal is depressed continuously for a specified time, the engine speed may decrease to the idle speed. This is due to the fuel cut control operation, which prevents overheating, and it does not indicate a malfunction.
a. Run the engine at 2,500 rpm for 5 min.
b. Maintain the engine speed at 3,000 rpm for 5 s, and then idle.
c. Repeat Steps (1), (2) several times.
13. Stop the engine, and inspect the engine coolant level after the engine coolant temperature decreases. If it is low, repeat Steps 8*12.
 
You want to do steps 12a and 12b several times to ensure the coolant circulated throughout the system. Dont just pop the cap open immediately or youll severely scald yourself. Piping hot coolant will fly out.

Let the engine cool off and inspect. Circulating the coolant and checking afterwards will ensure the system is filled to capacity and not low. Top off the radiator and repeat if low. You cant top it off via the reserve tank.
 
Wanting to do a coolant change.
Location of Block Drain plug and can I reach it?
Other plan-
Remove thermostat and leave radiator drain open while idleing the vehicle with garden hose in. Let it drain and fill with distilled water and drain 4 or 5 times. this will leave it with mostly nothing but distilled water in the block then fill up with concentrate.
So the question becomes if you simply drain the system at the radiator what percentage of the entire system is drained? If I were to have the block fill of disitlled water then topped off with straight AF what would my ratio end up being?

Considering this fluid in full strength
RAVENOL J4D2092 Coolant Antifreeze - HJC Hybrid Japanese Coolant Protect FL22 Concentrate (5 Liter)
https://www.amazon.com/dp/ (commissions earned)

Any other fully compatable FL-22 coolant that can be recommended?
Is there a previpous thread on full coolant flush change on the 2.5L? I find the search function to be smarter than me. Can't seem to narrow down the results.

15 liters! That's a lot of coolant!!! I bought the same stuff from Amazon but it was a 5 liter jug for $35. It seems that this jug is no longer available from Amazon.

RAVENOL J4D2092 Coolant Antifreeze - HJC Hybrid Japanese Coolant Protect FL22 Concentrate (5 Liter) $35.47
 
c. Repeat Steps (1), (2) several times

would be to ensure the all air is moved out of the cooling paths/low spots and engine to reach optimal temps for the thermostat to open the secondary pathway.
The water pump flow would also be higher at higher rpms because its based on the crankshaft rpms (engine rpms) so effectively more rpms increase the flow speed. Some manuals even recommend to,wait for the fans to kick in and checking pipes after thermostat.
Ideally the coolant expansion reservoir should be highest point.
Its imperative there is no air pockets in the system.
 
Fill the coolant as much as you can through the radiator cap, wait for coolant to settle and refill again to the top of radiator if needed then close radiator cap and only then then start the car. do not open the radiator cap anymore.
any additional coolant needed could be filled through the expansion tank, as the engine runs and self bleeds the air, the level may drop inside the expansion tank.
the cap on the expansion tank can be open at the time and keep refilling if needed. Engine has to be running.
After the whole procedure, check after few hours later when the engine is cold and refill if needed.
Check again in a day or two on cold engine and refill if needed. Do not overfill the expansion tank. If overfilled additional coolant can be drawn out with syringe. Wear proper gloves and be diligent.
 
Fill the coolant as much as you can through the radiator cap, wait for coolant to settle and refill again to the top of radiator if needed then close radiator cap and only then then start the car. do not open the radiator cap anymore.
any additional coolant needed could be filled through the expansion tank, as the engine runs and self bleeds the air, the level may drop inside the expansion tank.
the cap on the expansion tank can be open at the time and keep refilling if needed. Engine has to be running.
After the whole procedure, check after few hours later when the engine is cold and refill if needed.
Check again in a day or two on cold engine and refill if needed. Do not overfill the expansion tank. If overfilled additional coolant can be drawn out with syringe. Wear proper gloves and be diligent.

Thanks...This deviates from the official instructions a bit but is the process I was leaning more towards. In other words **I don't want to have to open that radiator cap multiple times**. I'm at 109-110k miles so in the spring 2020 its definitely a next project.

You could fill radiator to full, put heater on high, rev a bit and fluid will be sucked into system, fill more, repeat process until you can't no more. Fill expansion tank to full. Cool off. Check levels.

What do you guys think?
 
No need to put heater on max I think but later when you finish its a good test to see if there is residual air.
You would need to thermostat to open so that coolant circulates everywhere.
I think in the repair manual for 2015 cx5 you could see the diagram with all pipes.

So preferrably dont do it on a cold day :)
 
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