Coolant Flush

Forum for Infiniti M35 and M45, and Nissan Fuga owners.
Daniel23
Posts: 13
Joined: Tue May 15, 2018 7:17 pm
Car: 06 Infiniti M45
Location: Dallas, TX

Coolant Flush

Postby Daniel23 » Sun Nov 18, 2018 8:36 am

Hey guys, I've been searching and haven't found much on a coolant flush, perhaps user error ha. I thought it was time for a flush, however my car (06 M45) had conventional green. After a bit of research Infiniti recommends Nissan long life or equivalent which would be "Zerex Asian Vehicle Formula" (Blue). I put in a bottle of Cleaner and let it run for a few days. Afterwards, I drained what was in the radiator from the lower radiator hose. I added distilled water and repeated the cycle a few times. As of right now, the coolant is a light green due to the mix. As temperature begins to drop, the possibility of the water freezing is getting higher. I was reading the Service Manual to completely drain the coolant. It stated to "open water drain plugs on cylinder block." From the diagram I saw it seemed to have two, one on each side of the block. I was curious to see if anyone members had a few tips of wisdom for me, before I proceeded. I didn't want to mix conventional green with Zerex due to the possibility of creating sludge in the system. Anything helps!


EdBwoy
Moderator
Posts: 2934
Joined: Tue Dec 25, 2012 12:47 am
Location: St. Louis Metro East - IL
Contact:

Re: Coolant Flush

Postby EdBwoy » Sun Nov 18, 2018 9:59 am

I never feel the need to drain the engine until it's bone-dry. A drain and refill should be sufficient since you are replacing some old stuff with new/fresh stuff.

If you use the drain at the bottom of the radiator and open the cap and bleeder plug, you collect a little over a gallon.
At this point I add a coolant/antifreeze mix of 50/50 to equal what I drained out.
Do it a few times if you want to get as much old stuff out as possible.

Again, in normal service it's just a dilution process. No need for cleaners or a "flush" unless you are certain you have some bad stuff that needs to be gotten rid of.
Then you find the drain plugs on the block to completely drain it. Caution: they can be a pain to properly service and can end up being a source of leaks in the future.

My suggestion on coolant service:
  • No need for a flush or chemicals if the system is operating normally.
    Just use 50/50 mix. Either you do it yourself or you buy it premixed.
  • You can buy a tester kit to tell you how close to 50/50 your mixture is.
  • Color usually shouldn't matter, but you have to ensure the chemicals are correct. I use Prestone. It is green and compatible with both blue and green Nissan coolant.
My advice is to just go buy coolant from Nissan if you are unsure of the colors and mixing. That way you don't risk causing major problems that $50 of "proper fluid" could have avoided.
Here are the part numbers - https://forums.nicoclub.com/post6781535.html#p6781483

Daniel23
Posts: 13
Joined: Tue May 15, 2018 7:17 pm
Car: 06 Infiniti M45
Location: Dallas, TX

Re: Coolant Flush

Postby Daniel23 » Sun Nov 18, 2018 6:13 pm

Since the system already has distilled water, creating my own mix seems like the best way to go. It will make things a whole lot easier. You made great points which made me consider draining the entire engine block. Thank you for you for the input EdBwoy!!

EdBwoy
Moderator
Posts: 2934
Joined: Tue Dec 25, 2012 12:47 am
Location: St. Louis Metro East - IL
Contact:

Re: Coolant Flush

Postby EdBwoy » Sun Nov 18, 2018 7:12 pm

You're welcome. I've actually had to run a cleaner for a rusty system.
When the temperatures dropped afterwards, I had to run approx 6 gallons of distilled water through to flush/dilute the Thermocure which has no freeze protection.
By estimating the color of what I drained out, I poured in a gallon of concentrated antifreeze followed by some quantity of 50/50 mix
... Then I used a kit I bought at AutoZone for $3.
It told me my the estimation was pretty good for a 50/50 mix.

May luck be in your favor.

Larz
Moderator
Posts: 2618
Joined: Thu Feb 21, 2013 8:55 pm
Car: 2009 M35 RWD
Location: Ft Lauderdale, Florida
Contact:

Re: Coolant Flush

Postby Larz » Tue Nov 20, 2018 5:41 pm

I agree, as usual, with our resident expert Ed. His experimentations and his Youtube channel provide a plethora of valuable and interesting info on our Ms. I also agree with your idea to just empty out the entire block. Your car is 12 years old and if you don't know when the the fluid was changed last, it could also have 12 years of contaminants and the resulting weakness to prevent proper running temps.
Ed is right - just buy the actual Nissan coolant. The higher price might just avoid an astronomical price for a repair mlater on.


Return to “Infiniti M35 and M45 Forum”