Have a ten-year old Honda Civic. Several (but not all) folks that should know have said not to use an anti-rust inhibitor (to include antifreeze) in the radiator, but just use potable water. When I used to live in Hawaii (similar climate), I always used a 50/50 mixture of water and antifreeze, as did most others.

So, my radiator is now filled with water from my filtered tap (bottled mineral water not an option). Is this the way to go? Possibly those who told me to use only water know my car sits for several months at a time when I'm back in the States -- but I'm not 100% sure this was in their equation.

Recommendations?

Oh, remember back in the days when you could work on your car yourself (like, in the 60's). One of the gizmos most of us had (Stateside, anyway) was that backflush hose socket in our heater hose: open your heater, screw in your garden hose, warm up the car, and replace the radiator cap with the vent spout. Well, backflushing is a good idea -- but in Thailand, with no heater hose to attach gizmos to, how do you do this? I mean, the car has to be warm (thermostat open) to be effective -- but warming up the car, then popping the lower hose and jamming a garden hose into it doesn't seem too practical. Any Thai gizmos for this?

Oh, if rust inhibitor is recommended, what are the (best) options?

Thanx.

There are several reasons why you should run antifreeze in your tropical car. Clearly it would have nothing to do with the water freezing on you.

1) Antifreeze is a lubricant. Your water pump will last much longer with the use of antifreeze.

2) Antifreeze contains anti-corrosion agents. That includes protection against iron and aluminum corrosion. Your car likely has an aluminum head, and for weight control reasons some of the passageways in the head are relatively thin. Enough corrosion, and you develop a water leak into the wrong area of the head.

3) Antifreeze (50% solution) raises the boiling point of water a little higher. This (along with having a functional pressure cap on the radiator) helps protect you against boil over in slow traffic conditions, extremely hot conditions, with air conditioner on, etc.

You can get by with using tap water if the radiator doesn't lose much fluid over time. And if your water is "soft" (not much mineral content) then its better too. The problem with using hard tap water in a radiator that slowly loses fluid is that the minerals stay in the radiator as the water evaporates. This slowly clogs the radiator with something that looks like limestone.

So, I think the first two reasons are the most important for your application.

kenk3z

There are several reasons why you should run antifreeze in your tropical car. Clearly it would have nothing to do with the water freezing on you.

1) Antifreeze is a lubricant. Your water pump will last much longer with the use of antifreeze.

2) Antifreeze contains anti-corrosion agents. That includes protection against iron and aluminum corrosion. Your car likely has an aluminum head, and for weight control reasons some of the passageways in the head are relatively thin. Enough corrosion, and you develop a water leak into the wrong area of the head.

3) Antifreeze (50% solution) raises the boiling point of water a little higher. This (along with having a functional pressure cap on the radiator) helps protect you against boil over in slow traffic conditions, extremely hot conditions, with air conditioner on, etc.

You can get by with using tap water if the radiator doesn't lose much fluid over time. And if your water is "soft" (not much mineral content) then its better too. The problem with using hard tap water in a radiator that slowly loses fluid is that the minerals stay in the radiator as the water evaporates. This slowly clogs the radiator with something that looks like limestone.

So, I think the first two reasons are the most important for your application.

kenk3z

I agree with everything kenk3z said but would like to add that the best water to use is distilled water. With distilled water you won't get any mineral deposits in your engine, water pump or radiator...

Oh, remember back in the days when you could work on your car yourself (like, in the 60's).the lower hose and jamming a garden hose into it doesn't seem too practical.

And remember how much fun it was to gap those points!

Really don't miss those days as that job was a pain...

......Clearly it would have nothing to do with the water freezing on you. 

If you have an air-conditioner in the auto, the "AC Evaporator" is usually located next to the "Heater Core". Air is first blown throught the AC Evaporator, then the Heater Core before making its way to the dashboard vents.

As water from the engine cooling system is circulated through the heater core, if you do not use anti-freeze in the cooling system, your auto's air conditioner could cause water in the heater core to freeze and (as water expands when frozen) probably "crack" the heater core. Result.......a loss of engine cooling water, possible engine overheating, and warping of the alumnium heads (if car is so equipped).

Therefore, it is very important you run your auto's cooling system with anti-freeze installed.

A warped head or cracked heater core can be a very expensive repair.

Antifreeze/Coolant, same thing and you would do well to use it here. Most have an anticorrosive additive which will help the inside of your engine. Use a quality flush/cleaner for maintenance. As long as you do this, I don't see the need to backflush the engine as I would think the radiator would be more likely to plugup than anything else and this is easier to do.