Coolant Flush

[RPGR90s]

I have a question. The other day I wanted to do a coolant flush on my 2019 ST. The car was purchased now and currently has 103k miles. It's been a perfectly flawless vehicle.

 

At the 1st coolant service, I had the Ford dealer flush and re-fill. They swapped out the original orange colored coolant for a green colored coolant. 

 

Now I see that the latest Ford coolant is yellow colored, so that's what I purchased. 

 

I found the drain (boy what a fun job it is getting access to THAT!!) and drained the old coolant. 

I then added a coolant flush with distilled water and let the car come up to temperature.

I ran this for the specified interval (10 minutes) and drained again.

 

The liquid coming out was mostly clear so I filled the tank with the new, yellow colored coolant and brought the engine back up to temperature. 

 

I let the car cool down over-nite and in the morning the tank was a bit low, so I topped it off.

 

But what caught my eye was the coolant reverted back to a solid green color. 

 

Did I miss a step in my probess and possibly not get all the old coolant out?

 

Thanks for any advice or direction.

 

RPG

 

[1004ron]

Running the coolant flush for only 10 mins would not have warmed up enough to open the thermostat and you should set the cabin heating to MAX for it to circulate through it.

[RPGR90s]

3 hours ago, 1004ron said:

Running the coolant flush for only 10 mins would not have warmed up enough to open the thermostat and you should set the cabin heating to MAX for it to circulate through it.

If I recall, the engine was already at max temperature and I did have the heat set to Max.

 

Thank You!

[Samurai Edge]

Just remember you are not completely draining the coolant from the engine with a normal flush.  Old coolant will still reside in the engine so this may be the cause of your " green "coolant.

[1004ron]

The only way to get only the new coolant in the system is to do a few drain-fills with distilled water and then the final fill with a higher concentration of the new coolant expecting some distilled water to remain in the engine.

 

 

[Samurai Edge]

One could also use a system like the following to flush out the entire system and then fill with concentrated ( non-diluted ie; 50/50 ) anti-freeze

 

https://www.amazon.com/dp/B0002SRH5G/?coliid=IBXVQ52CJGVOB&colid=1VY88PYQ3KPE1&psc=1&ref_=list_c_wl_lv_ov_lig_dp_it

 

[johnmarkp]

Not sure why you recommend pure antifreeze?  Pure ethylene glycol freezes at 10f.  The normal 50:50 mixture freezes at -35f.

[1004ron]

1 hour ago, johnmarkp said:

Not sure why you recommend pure antifreeze?  Pure ethylene glycol freezes at 10f.  The normal 50:50 mixture freezes at -35f.

Not sure who that comment was directed at?

 

I always buy the concentrate and mix it 50/50 and the product details state clearly not to go higher than 60/40.

 

My comment was to drain/fill a few times with distilled water and that way you would have removed about all of the old coolant mix, then go back with say a 60/40 mix knowing that the engine still contains some straight distilled water.

 

I use a vacuum fill kit similar to this. 

Edited 1 hour ago by 1004ron

[Samurai Edge]

2 hours ago, johnmarkp said:

Not sure why you recommend pure antifreeze?  Pure ethylene glycol freezes at 10f.  The normal 50:50 mixture freezes at -35f.

 

I stated concentrated, ie; non-diluted, because when you flush the system as described, you will be left with water still in your system.  By using the concentrate, you will be close to a 50 / 50 mix.

 

BTW, the concentrate is cheaper than the 50/50 mix from the supply store and you are paying for water.

As 1004ron said, I also buy the concentrate and dilute on my own