A word of advice: Never buy local auto parts stores' thermostats. They are obviously cheaply made as can be determined from their price. Once I take pictures, I'll post. The OEM is a lot better yet more expensive.

My car is not overheating anymore. I changed coolant to pre-mixed Prestone coolant, changed thermostat to Honda OEM, changed radiator cap, and tried to get as many bubbles out of the system as I can.

On the D-series engines, there is another drain bolt on the back of the block to the left of the oil filter. (B-series engines are lucky to have them in front of the block.) Anyways, on a D-series the bolt is torqued to God-knows-what. It's damn hard to get off and I quit. The axle in the way doesn't help either. There is no way I'm popping off that axle again, because I'd have to disconnect my downpipe and catalytic converter to do that.

As stated before, I feel that some of my troubles were attributed to using only water+Redline Water Wetter which I believe does not work well in colder temperatures.

 

You have to take the down pipe and converter off ot get the axle off? nver heard of that. The plug in the back of the block is really only meant to drain the block for major work. I have never taken that plug out just to do a drain and refill.

 

Yea, I wish it wasn't like that. I have a rebuilt NAPA driver-side axle. The inner boot was longer than my stock one. It fits though so I don't care. There is a bracket that holds the factory exhaust manifold, which currently holds my downpipe. The bracket interferes with the axle and that's why I currently have the bracket wrapped in heatwrap to avoid ripping my axle boot.

Eh, it's better to explain with pictures.

 

isn't it supposed to be 65/35? It does help a lot, it dropped my friends JRSC lude coolant temp around 40 degrees.

 

If I remember right according to my manual it's 50/50. Too much water in the system and it can still freeze up with anti-freeze.

 

it's 50/50.

 

This is from the back of Texaco 5 yr/150K mile coolant (silicate free, OK for Hondas).

40% coolant : -7 F freeze protection, 260 boilover
50% : -34, 265
66% : -84, 270

So yes, you need AT LEAST 50% concentration to give decent freeze protection - in addition, I don't think lower concentrations give you adequate corrosion prevention.

I believe higher concentrations beyond 66% will give you lower freeze points but actually reduce the boilover point.

 

actually 50/50 can have you overheating.

in wisconsin we have to change our mix. in summer we can be almt 100% water, but in winter its something like 66%/33%.

the best thing to do is get a hydrometer, its like $8 and then you know its right. you people are so concerned with following the manual, and to be frank it's not really based in the real world...its based in a world of 0 variables and perfection...its a midstream to cover hondas ass in respect of florida, california, and canada temperature extremes. you -should- be using a hydrometer.

just from scott's chart i know i would have to be nearly 60% antifreeze in the winter or i could lock up. and in the summer that same mix would see me popping my head.

 

If your cooling system is working properly, you should never see temps much over 200-210 F. I live in NC and I know the concentration in my Civic is pretty high - my hygrometer is pegged at -43 F, which is about 60%. I live in NC and it gets pretty damned hot here, but the Civic's gauge has never moved off the middle of the temp gauge. If you tend to overheat, check the functioning of your thermal switches - my mother's 89 civic (in PA) had all kinds of problems this summer, had to replace both fans and the thermal fan switch.

A chart on a regular prestone bottle I have says the best protection is at 70% coolant - -84 freezing, 276 boilover. But I believe above 70% is where the boiling point starts dropping.

You should NEVER run even near 100% water - it will not take long to corrode away your cooling system. I don't know why you would want to anyway, pure water will boil at around 220 F IIRC (under 1 atm pressure, at the normal 15 PSI radiator cap)

 

antifreeze is a less effective coolant than water, much less. the only reason its there is for anticorrosion and anti freezing.

i use a hydrometer, my temp never goes about mid level unless i drive very hard on a vrey hot day. you know the day when your clutch smells at the end...