Coolant Replacement for Dummies

[djburke87]

Hey guys, I'm a dummy that doesn't know the details of coolant replacement. I swapped all my hoses yesterday for the Z1 silicone hoses (easy except the heater hoses which are a nightmare).

So now I'm replacing my coolant. Here is what I've done:

Filled the coolant until it ran out of the bleeder plug on the driver's side.

Plugged the plug back in.

Filled it until the reservoir was on max.

Put the reservoir cap on.

Put the coolant funnel in the radiator cap ( the one nearest the engine).

Ran the engine for about 10-15 minutes with revs.

Ran the heater for a while.

Let it cool down.

Ran the engine for about 10-15 minutes with revs.

Ran the heater for a while.

Let it cool down.

....

So now what? Do I just take the funnel out a replace the cap? What aboutt the air before the radiator cap, is that going to matter? I'm probably overthinking this, but I really don't want to screw it up.

Everything I have seen for the 370z and G37 has a different reservoir that I do. I have the stock on for a 2018, which has the pressurized cap on the reservoir and on the radiator.

Any help is appreciated!

[JARblue]

help with coolant flush

Originally Posted by REVRAY

Draining INFOID:0000000008193252
WARNING:
• To avoid being scalded, never change engine coolant when the engine is hot.
• Wrap a thick cloth around radiator cap and carefully remove radiator cap. First, turn radiator cap a
quarter of a turn to release built-up pressure. Then turn radiator cap all the way.
1. Connect drain hose.
NOTE:
Use a general-purpose hose with the dimmensions shown in the
figure.
A : MAX
B : MIN
JPBIA0102ZZ
Testing pressure : Refer to CO-29, "Radiator".
PBIC5121J
A : φ15 - 16 mm (0.59 - 0.63 in)
B : 145 mm (5.71 in)
JPBIA4770ZZ
Revision: 2012 August 2013 370Z
ENGINE COOLANT
CO-11
< PERIODIC MAINTENANCE >

2. Open radiator drain plug (2) at the bottom of radiator, and then
remove radiator cap.
When draining all of engine coolant in the system, open water drain plugs on cylinder block. Refer
to EM-79, "Setting".
3. Remove reservoir tank if necessary, and drain engine coolant and clean reservoir tank before installing.
4. Check drained engine coolant for contaminants such as rust, corrosion or discoloration.
If contaminated, flush the engine cooling system. Refer to CO-13, "Flushing".
5. Disconnect drain hose.
Refilling INFOID:0000000008193253
CAUTION:
• Do not reuse O-rings.
• Do not put additive such as waterleak preventive, since it may cause cooling waterway clogging.
• When refilling use Genuine NISSAN Long Life Antifreeze/Coolant (blue) or equivalent in its quality
mixed with water (distilled or demineralized). Refer to MA-16, "FOR NORTH AMERICA : Fluids and
Lubricants" (FOR NORTH AMERICA) or MA-17, "FOR MEXICO : Fluids and Lubricants" (FOR MEXICO).
1. Install radiator drain plug.
CAUTION:
Be sure to clean drain plug and install with new O-ring.
If water drain plugs on cylinder block are removed, close and tighten them. Refer to EM-118, "Disassembly
and Assembly".
2. Remove air cleaner case (LH). Refer to EM-31, "Exploded View".
3. Install reservoir tank if removed.
4. Check that each hose clamp has been firmly tightened.
5. Remove air relief plug (2) on radiator left side.
1 : Engine under cover
A : Radiator drain plug hole
: Vehicle front
JPBIA0259ZZ
Tightening torque : Refer to CO-16, "Exploded View".
1 : Reservoir tank
3 : Engine cover
: Vehicle front
JPBIA0260ZZ
Revision: 2012 August 2013 370Z
CO-12
< PERIODIC MAINTENANCE >
ENGINE COOLANT
6. Fill radiator, and reservoir tank if removed, to specified level.
• Pour engine coolant through engine coolant filler neck
slowly of less than 2 (2-1/8 US qt, 1-3/4 lmp qt) a minute
to allow air in system to escape.
7. When engine coolant overflows air relief hole on radiator, install air relief plug with new O-ring.
CAUTION:
Do not reuse O-ring.
8. Repeat step 6.
9. Install air cleaner case (LH). Refer to EM-31, "Exploded View".
10. Install reservoir tank cap.
11. Warm up engine until opening thermostat. Standard for warming-up time is approximately 10 minutes at
3,000 rpm.
• Check thermostat opening condition by touching radiator hose (lower) to see a flow of warm water.
CAUTION:
Watch water temperature gauge so as not to overheat engine.
12. Stop the engine and cool down to less than approximately 50°C (122°F).
• Cool down using fan to reduce the time.
• If necessary, refill radiator up to filler neck with engine coolant.
13. Refill reservoir tank to “MAX” level line with engine coolant.
14. Repeat steps 11 through 13 two or more times with reservoir tank cap installed until engine coolant level
no longer drops.
15. Check cooling system for leakage with engine running.
16. Warm up the engine, and check for sound of engine coolant flow while running engine from idle up to
3,000 rpm with heater temperature controller set at several position between “COOL” and “WARM”.
• Sound may be noticeable at heater unit.
17. Repeat step 16 three times.
18. If sound is heard, bleed air from cooling system by repeating step 6, and steps from 10 to 17 until engine
coolant level no longer drops.
19. Check that the reservoir tank cap is tightened.

[djburke87]

I have read that many times.

[JARblue]

Are you checking the reservoir after each time you run it? How many times have you refilled it to max line? It might just take a couple of times or it might take 6-8 times. Once the fluid level no longer drops in the reservoir then you should be good. If it is still dropping you can do things like squeeze the upper radiator hose or lift up the reservoir to help burp air.

[djburke87]

I used one of those radiator funnels and ran the engine. The reservoir seems to come back to the same level every time I turn the car off.

[JARblue]

Did any air at all bleed out of the system? I guess it's possible if you poured in the coolant extremely slow. Typically you'll need to refill the reservoir at least a little bit.

[djburke87]

It bubbled a lot in the funnel while I was running it.

I just drove it about 20 miles going from 25-70MPH. The reservoir is at the same place as it has been. I guess it's good. I'll check it daily for the next week. I was just paranoid that I would screw it up. It seemed too easy!

[JARblue]

Originally Posted by djburke87

It seemed too easy!

Better than the alternative! Sounds like you are good to go