s2kjin

Hi All,

A couple days ago I took a short road trip with my S (approx. 2 hour trip one way) and noticed that on the way back, my heater was not blowing hot air anymore.
Got home and saw that the coolant in the reservoir was about 1 cm below the Low level. It was sitting between the High and Low mark ever since i've purchased the S back in May. (I check my fluids on a weekly basis)
Can't find any physical evidence of leaks, no coolant in the oil (probably wont be able to tell as it is probably only a cup or two of coolant).
I'm planning to flush out my Green coolant (type 1?) and switch it to the blue type 2 coolant.
I can't seem to find a D.I.Y thread for this procedure, and have never done anything related to the cooling system.
Would draining coolant and run the car on only distilled/demineralised water for a couple of minutes be enough to clear out the old coolant from the system?
How many times would it be recommended?
Thanks

Mr.Matchbox

This: https://www.s2ki.com/forums/s2000-un...bleed-1067218/

and the original workshop manual maybe come handy for location of parts.

s2kjin

Thanks for the reply.
I've looked into that before.
Was wondering if i needed to do that process with distilled water, and repeat it again with the Type 2 coolant.
Don't want both of them to mix, in case it may cause an issue later on.

Chuck S

Distilled/demineralised water is a better coolant so it won't hurt anything. Better means more heat transfer. Up to a point.

The typical engine coolant (50-50 mix of water and antifreeze) has the benefits of higher boiling and lower freezing temperatures, and typically anti-corrosives added to protect the engine parts.

Boiling water is dangerous and a pressurized system even more so.

Boiling:
Unpressurized:
Water: 212°F
50-50: 223°F

Pressurized:
50-50 Capped: 253°F 1-Bar/14.5psi radiator cap. Ours are 1.1-Bar so even hotter. 275°F?

-- Chuck

s2kjin

Thanks for the reply Chuck.

Does this mean i should fill it with distilled water, bleed the air out and running the car a couple times before it gets too hot?
Would this process flush out all the remaining green coolant?
Also im not sure if the remaining distilled water will dilute the 50/50 type 2 coolant that im going to put into the system.

Sorry, im a noob at car mechanics, just been starting to learn how to maintain and fix stuff on my S

flanders

Just drain as much of it out as you can, there is a plug on the side of the block that can be loosened if you really want to go all in (or all out :P).
Maybe pour some distilled water through the radiator if you want to flush it some more.
Leaving some residue of old green coolant isn't going to cause any problems though.

Chuck S

If this was my car I'd just drain the offending antifreeze and replace with Honda Type 2, but flushing the system with water won't hurt. Just needs to be clean water -- tap water will do fine, this is neither medical equipment nor a nuclear reactor. And it's coming out in a few minutes. Open all the bleeder plugs (I know of 2 but Flanders indicates there's a third one) when draining. Walk away, have lunch, let every last drop drain, and then close the bleeders and refill.

Refilling using the "Leslie"(brand) funnel is simple. Burping the system to get the remaining air out requires squeezing the upper radiator hose which will be hot and requires some grip strength. I used clamps to keep the hose squeezed with the bleeders open, then closed them and released the clamps with the funnel still in the radiator.

Take your time, the fluid will be scalding.

Don't anguish over any residue from the old coolant. No one worries about the engine oil residue during an oil change and there's 0.8 liters of old oil left in the engine even when drained dry. (Holds 5.6L after a rebuild and only needs 4.8L during an oil change.)

-- Chuck

Thomas Guide

Here's a video using the burp funnel on a S2000 as the other method described in the Billman thread:

Chuck S

Should be a "sticky." It's as easy as it looks and the clear hose on the bleeder valve is a great tip.

Since all our cars are now over 10 years old the antifreeze should be changed every 5 years. Don't know when, or even if, it was changed? Just do it now and mark your calendar for 2024.

I borrowed @Birdybog 's .

-- Chuck

jyeung528

i don't think it's from your low reservoir, the pickup tube extends pass the level that you're at.

did you recently do any work with the coolant or system?

assuming you have bled the air out, have you checked the operation and adjustment of your heater valve?