Honda Pilot - Honda Pilot Forums banner
1 - 20 of 63 Posts

·
Registered
Joined
·
57 Posts
Discussion Starter · #1 ·
Hi all, I’m trying to change my coolant and opened the valve under the radiator. However, only less than 1 gallon flowed out.

I know this because I put new distilled water in and couldn’t fill a gallon. Then I warmed up the car and opened the valve again.


Question is, according to the manual our coolant capacity is 2.25 gal. After flushing it with distilled water, am I diluting the coolant that’s within the block? Will this have any adverse effect in the winter?

Of course after the final flush, I plan to put in new blue Honda coolant. But afraid that by flushing it a few times, the old coolant is diluted by distilled water.
 

·
Registered
Joined
·
1,019 Posts
Did you remove the radiator cap while draining? Does Honda make a concentrate AF/C vs 50/50? Lots of help I am.....answering your question with questions, sorry.

Be sure to drain/refill the recovery bottle. Be sure to check both the recovery bottle AND radiator, MOTOR COLD, for several days, several heat/cool cycles. Burping the cooling system takes several heat/cool cycles.

Doesn't look like Honda makes a concentrate AF/C, so how do you get to the proper 50/50 mix in the cooling system when the cooling system is more than half full of +/-99% water, after a flush?🤷‍♂️

Can the block be drained? 1 or 2 plugs? if so, are they a beach to reach.
 

·
Registered
Joined
·
11,364 Posts
I think draining and flushing the system with distilled water 3-4 times is an excellent way to remove the old. Warming up the engine to operating temp between each drain and fill. And of course, don't forget to turn the heater on to flush the old coolant from heater core.
But now, your question is a valid one. You have a system partially filled with distilled. 50/50 will not bring your system up to the proper mix. This is why I use Prestone Concentrate. Then use a tester to get a 50/50 + mix.
140580

140579
 

·
Registered
Joined
·
57 Posts
Discussion Starter · #4 ·
Yeah. I opened the radiator cap. Did this process three times with distilled water/ warm up car/ heater on high and driving around a bit while watching the coolant temp on the ODB scanner.

I have premixed coolant, guess the only solution is a concentrate solution.
 

·
Registered
Joined
·
1,019 Posts
Prestone makes a AF/C with blue food coloring.....but not in a concentrate. Peeps at Prestone/Honda are not using their noggins.

I ran into the same situation after draining/flushing our RAV4. Prestone AF/C concentrate solves the problem......but it does not have ‘yota red food coloring.
 

·
Registered
Joined
·
11,364 Posts
I've been using Prestone concentrate for a long time it's never let me down. And it's $10.87 a bottle at Walmart!
140583
 
  • Like
Reactions: ConrodM and PLT383

·
Registered
Joined
·
1,019 Posts
Yeah. I opened the radiator cap. Did this process three times with distilled water/ warm up car/ heater on high and driving around a bit while watching the coolant temp on the ODB scanner.

I have premixed coolant, guess the only solution is a concentrate solution.
How did the old coolant look?......cloudy, particles in the drain pan?
 

·
Registered
Joined
·
1,019 Posts
I've been using Prestone concentrate for a long time it's never let me down. And it's $10.87 a bottle at Walmart!...........
Over the years, I’ve replaced DEXCOOL and ‘yota red coolant with the green/yellow stuff......never an issue.

Heck, I’ve even added non-Genuine Honda air (80% nitrogen) to the tires.😱
 

·
Registered
Joined
·
1,019 Posts
Honda makes a coolant concentrate.

Coolant Concentrate

There is a drain fitting on the engine block that is used to drain the coolant from the block when doing a coolant replacement. To me, that is the easiest way to get all the old coolant/water out.
Ah Ha........good find, my bad. I did not see it at College Hills Honda. Give me a hint where the drain fitting is, please.

If you can get 4 qts of the concentrate in, you'll be close(er) to 50/50.

Wonder why it says "Do not add water"? 🤷‍♂️ You would be adding it to water, right?
 

·
Registered
Joined
·
57 Posts
Discussion Starter · #12 ·
Honda makes a coolant concentrate.

Coolant Concentrate

There is a drain fitting on the engine block that is used to drain the coolant from the block when doing a coolant replacement. To me, that is the easiest way to get all the old coolant/water out.
Where is that drain located?
 

·
Registered
Nobili spiritus embiggens pequeño sparus tyre.
Joined
·
10,238 Posts
Where is that drain located?
A little shaky, a little blurry, a little taciturn on the narration (except for some heavy breathing), but this might help.

 

·
Registered
Joined
·
1,019 Posts
Awesome, thanks. (y) (y)
 

·
Registered
Joined
·
1,019 Posts
It looked fine, pretty clean overall actually.
I'm kinda thinking of just doing a drain (at the radiator) and fill.....no flush, that way the motor still has 50/50 and 50/50 will be added to it. Just thinkin'........🤷‍♂️
 

·
Registered
Joined
·
312 Posts
Passengers side, firewall side of the engine.


You could use some of the regular 50/50 antifreeze and some of the concentrate to make up for the distilled water in the system, if you decide not to drain the block. If you drain the block I would just use the normal 50/50 stuff.

They say not to dilute the concentrate to simply to give you a lower freeze point.
140593
 

·
Registered
Joined
·
1,019 Posts
Awesome, I’ll have to look next time I’m underneath........now the 50/50 will not be diluted.👍

Still puzzled why the Honda concentrate says “do not add water”. Must be if you add water, no longer have -62 freeze protection.🤷‍♂️
 

·
Registered
Joined
·
312 Posts
Yea. They are saying don’t dilute the concentrate because it will raise the freeze point.

You don’t ever want to dilute the 50/50 stuff.
 

·
Registered
Joined
·
1,019 Posts
Passengers side, firewall side of the engine.


You could use some of the regular 50/50 antifreeze and some of the concentrate to make up for the distilled water in the system,.................
If you have water remaining in the cooling system, I don't think you would want to add anything but concentrated AF/C to the system.....nothing predicted.👌 If the system holds 9 qts, and you can add less than 1 gal of concentrate, you still have a higher % of water than AF/C.
 
  • Like
Reactions: ConrodM

·
Registered
Banned from wife’s 2005 Pilot LX
Joined
·
4,174 Posts
Awesome, I’ll have to look next time I’m underneath........now the 50/50 will not be diluted.👍

Still puzzled why the Honda concentrate says “do not add water”. Must be if you add water, no longer have -62 freeze protection.🤷‍♂️
I think Honda assumes you have 50-50 Honda blue coolant in the system, and that if you’re adding concentrate that the goal is to lower the freezing point.

In your case your coolant to distilled water ratio is lower than 1:1, so you’re using the concentrate to get to the 1:1 ratio.
 
1 - 20 of 63 Posts
Top