O.K. then, go for it. When you drained the Coolant, have you set the heat to MAX to allow all coolant in the heater core to escape?

 

Different car, but my 2002 Tacoma was filled by a previous owner with Prestone. It took me three fill and drains (and runs) before the distilled water was clear. Then premixed Toyota coolant.

 

I did.

I'll repeat the process as many times as is necessary until I get clear water.

 

The dealership didn't have one in stock, so they had to order it. The part number is 90401-PR4-000. I should have it tomorrow.
90401-PR4-000 - Genuine Honda Washer, Sealing (28MM)

The description says 28mm, but the bolt head is actually 19mm. This washer is used on a ton of cars, so the fact that the dealership didn't have one in stock tells me that they don't drain from the block when changing coolant.

 

According to the Service manual you can expect to drain 1.72 US gallons out of the cooling system during a coolant change and 2.01 gallons at an engine overhaul. Nearly 15% of whatever is in there doesn't come out with a mere coolant change.

Without completely tearing down the engine every flush and fill with the replacement fluid (say water) cuts that percentage in half. Rounding to a handy initial 16% left behind on the first change we get 8%, 4%, 2%,1% -- almost four (4) ounces left behind after five (5) changes... Got 10 gallons of distilled water? Of course since you've used water when you finally get back to antifreeze there's gonna be that 16% of water left behind...

For some strange reason Honda doesn't think it's a problem just doing a coolant change.

-- Chuck

 

You could have worse stuff in your engine than distilled water, honestly. And at worst, it'll just cut down the premix ratio. It would honestly take way too much work to flush it all out.

Just drain and fill. I actually need to do mine now that I think about it.

 

They know it isnt ideal therefor call for more frequent coolant changes after the first drain and fill.

 

I figured out why my local Honda dealership doesn't remove the bolt on the engine block to drain the coolant. It seems to be impossible to turn off. From under my car that was on my life, I had a straight shot with an extended ratchet. With a ton of force, all I managed to do was round off the bolt head a bit. It's simply not moving. So, forget that idea.

On the plus side, I figured out a way to remove more trapped air from the system. In most of the videos that I watched, people closed the bleeder valve after filling the radiator. I left it open and ran a tube to a water bottle. When I warmed up the car, a ton of air came out of it. I had to empty the bottle a few times as some water came out along with the air. The water is much lighter green. After air stopped coming out of it, I turned off the car. Then some more air came out. I'll let it cool and then repeat the process one more time.

 

Coolant changes are to keep corrosion out of the system. You could likely go longer but why risk it? The water pump on this car is one of the most reliable ones ever built.

 

I opend the bolt, it is a BIG hassle. It is best a two man Job (One turning the wrench, one pressing the ratchet and nut firmly into position) with the car on the lift. I will never do this again.
Regarding the bleeding, i prefer the LHT method + opening the Bleeder at the firewall. Have a read: https://www.s2ki.com/forums/s2000-un...y-way-1218970/