I'm going to give a bit of history for those who don't know what I have, which is likely everyone. I'm giving a lot of info just so people don't have to wonder about this and that. Please bear with me.

I have a 1994 Mazda Protege LX. It has a 5 speed manual transmission, DOHC BP engine. I bought it brand new and other than a warranty repair, calliper cracked on the rear passenger side, no one has worked on the car but me. This would exclude tires and a recent exhaust replacement from the cat to the rear bumper. So, just about all repairs is done by me from birth. I'm also working on getting the pipe from the exhaust manifold to the cat. Sort of having issues with that one but that's in another thread. I currently have just over 192,000 miles on the car.

Many years ago, I did my first anti-freeze change. I think the car was about a year or so old at that time. When I changed it, it was thicker than I expected and extremely clean, so I tested it. Mazda had put straight 100% anti-freeze in there. I was surprised but I put 100% anti-freeze back in, figured that they did it for some good reason. I been doing this ever since. The engine has never ran hot, not once. I have left the car running on hot days with the A/C running and it still does not run hot. The gauge goes up about half way but never any higher.

Some more history. I replaced the timing belt at about 100,000 miles. I replaced the water pump, just because I was looking at it and didn't want to come back a month later to see it again. It was very clean. No corrosion, bearings sounded good but I changed it anyway. So, water pump changed just because it was a wise thing since it is hard to get to.

At about 6 or 8 years old, I changed the upper and lower hose that goes to the radiator. When changing the oil, I noticed the bottom hose had a bad spot on it. It looked like something hit it. It wasn't leaking but it looked pretty bad so I replaced both hoses and the thermostat. I also replaced the sensor that goes on the thermostat housing. I think it goes to the gauge. It was working but the glue that holds the connector was bad and it was sort of loose. I wasn't sure if it could start leaking so it got replaced. Naturally, it got fresh anti-freeze again.

A few years ago, the plastic top on the radiator cracked. I replaced it. I also put in straight anti-freeze again. I looked at the insides of the old radiator and it looked brand new. I mean it was spotless on the inside. Other than the bugs on the fins, you could not tell which was many years old and which was new.

This car still has all the original hoses except for the upper and lower ones that I mentioned earlier. All the hoses that go to the intake, heater core and such are the original hoses. Basically, the only reason a hose was changed is because of external damage. I have never had a hose to fail on me.

Also, I use Prestone anti-freeze, the 5 year stuff. I usually change it every 4 years tho. I also put in a small bottle of the lubricant for the water pump and it is supposed to help make the coolant do a better job. I do this every time, the same way, the same stuff.

Remembering that I have basically never had a cooling problem with my car, that the system is very clean internally, and that everything works as it should. Should I just keep putting in straight anti-freeze? Keep in mind, it had that when I bought it. I'm not sure why but it did.

My concern, if I start putting water/anti-freeze mix in it now, I'm going to start having issues. I don't want issues. I might also add, when I changed the anti-freeze in my Moms car, 1985 Mazda 626, I put straight anti-freeze in it too. Even tho it was a used car when we bought it, it has had no cooling issues. The only thing I put a mix in is my Chevy truck. It holds way to much to chance straight anti-freeze in there. It holds like 3 or 3 1/2 gallons. My car and Moms car only holds a gallon or so.

I'm about to do a timing belt change and MAY replace the water pump. If I do, I want some opinions on whether to put in mix or straight.

Thoughts?

Thanks much for at least reading this far.

 

You will actually get better cooling performance and a higher boiling point with a water/af mix rather than 100%. What kind of antifreeze are you using?

 

I use the Prestone 5 year kind. This is what it looks like here lately.

Buy Prestone Extended Life Antifreeze/Coolant (1 Gallon) AF2000 at Advance Auto Parts

I don't buy it there but that is what it looks like. They change that jug every time I go to get some.

One thing I do like, every time I am able to see something that the coolant goes through, it is clean like new. The old radiator was clean as a whistle. The water pump I replaced when I changed the timing belt, clean as a whistle. Seriously, I have had basically zero cooling problems. Nothing has corroded, busted or anything that relates to cooling. The only thing that a person may could say failed would be that sensor that I had to replace. Thing is, it was working but the connector was loose. It was NOT leaking or anything. It has also never ran hot, not once.

My Chevy truck, I have had to clean that radiator out several times. That thing is a pain in the butt to deal with. Hoses don't last long, radiator always has some issue etc, etc. I think the water is causing this and I don't want all that with my car. I depend on my car big time. I might add, I love my little ride.

Just looking for thoughts on this. I sort of like it like it is but people say I am going to blow up something. Also, no oil leaks. The engine is clean on the outside. I clean it about once a year just so I can tell if it starts leaking. So far, doing good. Just dust and such.

Thoughts?

 

What kind of water you use, the best to use is the distilled with no minerals in it otherwise the minerals precipitate out of the water over time and plug things up.

 

I used to use city water but when I get the leak in the radiator fixed, I plan to get distilled water and put in the truck. They have that at Walmart and it is cheap. I'm not to worried about the truck tho. I'm mostly curious about the Protege and running it straight. I'm leaning toward doing the same thing since it works so well and I have had zero problems doing it this way. It doesn't cost much since usually one jug does the change. I have thought about putting Hy-Per Lube Super Coolant instead of the Prestone stuff I put in now. People say it is some good stuff. I dunno.

I thought about doing this. I have a IR temp tool. Maybe take a few measurements in places on the engine block. Take notes and such. Then put in a little water, maybe 40%, then repeat and measure the temps. If it runs cooler with the water, then maybe I should add some water when I change it. If it doesn't change, then maybe I should just run straight antifreeze like I have since I bought it. I just don't want to start having hoses busting, water pumps failing and all that sort of stuff.

Thanks for the replies tho. At least I am getting a opinion from someone familiar with Mazdas.

 

Your talking to the guy that has 5 egg whites in his 323's cooling system ROFLOL, cant afford to replace my radiator yet but the eggs are holding it together. I will try to find some good information for you

 

I used to have a 323. That was a neat little car. I drove it until it was about to die then traded it in for another Mazda. lol

I did find this:

Cooling System Additives - Turbo and High-Tech Performance Magazine

What I don't get is this. People tell me I am going to blow something up and that my car just can't run like this. But, it is 18 years old, has 192,000 miles on it, never ran hot and it runs great. The biggest set back I have had is when I tried to run gas with ethanol in it. That tore up some stuff. First the plugs messed up, then I had a plug wire to go bad, then the sensor in the distributor went out, I got a nice error code from the computer on that and a car that won't start. Dang ethanol cost me about $300.00 to fix. That distributor is not cheap by any means. I also had to clean out the fuel lines and replace every fuel filter on it, including in the gas tank. That was gross but the tank itself was clean. No signs of rust anywhere.

Anyway, I just want to keep my car running for a VERY long time. I'm disabled and I hope to drive this car until I die or they no longer have gas for me to buy to put in it.

Thanks.

 

Chiming in here:

Straight antifreeze is basically Ethylene Glycol with antioxidants added. It has a very low freezing point and a very high boiling point. However its ability to absorb heat energy is limited. Also it is slippery which provides some lubrication.

Water has a high freezing point and when it freezes it expands with such force that it could crack engine blocks. As a precaution engine blocks have freeze plugs. Water has no lubricant properties, (except as super critical steam but that's another topic). On the other hand, water has a very high capacity to absorb heat.

You did well with your 323 (mine was blue) and protege because the cooling system turns over fast enough to prevent overheating.

I don't see any reason why you should change a thing. You made no modifications that require a better cooling performance than what you have now. In the article they stuck a big engine in a small engine bay.

I think the insides of your cooling systems are this clean because of the antioxidants and the fact there is no water present. Water would promote electrochemical activity, using up the antioxidants. I would speculate that you could extend the flushing intervals.

Also I can imagine that the lack of water reduces the pressures inside the cooling system. That may have helped the longevity of your hoses.

Interesting stuff...and it reminds me I have to flush the system in my Protege.

 

I don't disagree with your explanation. I talked to a guy on amazon forums and he talked like I was going to just plain kill my engine. He wasn't coming out and saying it but he was implying it. Then when my temp measurements, years I been running it that way, the fact that my system is so darn clean and it has NEVER ran hot, he resorted to implying I needed to go to a hillbilly convention. I'm not a hillbilly. To me, that just killed anything else he had to say. I have always heard, when you get to the point of name calling, you lost. You have ran out of explanations and/or ideas. This is 200% true when dealing with politicians but that's for another site. lol

Did I say that others should do what I did, absolutely not. I would NOT recommend a person do this in a heavy duty truck, a turbo charged engine, race car or some other engine that has a lot of modifications to it. A person could try it and see if it works but they should watch everything like a hawk until they are sure it is safe. I'm talking about a really hot day, A/C running and maybe idling on some hot pavement or something. Basically, worst case as far as heat goes. If it survives that while staying cool, THEN maybe it is safe.

There is a HUGE difference in what I did and telling others to do the same especially with something that has huge loads or has been modified. I even said, this is specifically for my car and my results.

I had something interesting to happen today. I had to take a friend to the Doctor about 70 miles away. They have a Harbor Freight store there. Well, I found a IR temp tester on sale. $19.99 and I bought it. This one has a laser so that I know where I am pointing it. I already had the mini version but with no laser thingy so I was shooting blind. Anyway, after getting through with the running around up there, we drove a good 80 miles all the way back to the local drug store. I left my car idling and got out and started measuring the housing for the thermostat. I got as close as I could without getting onto the head/block parts. I figure that should be roughly the hottest place before going to the radiator. The highest I measured was 192F which is what the thermostat opens at. Right after that the fans cut on, literally seconds after. After the fans turned off, it was down to about 185F or so. I would think the thermostat was closed and would go back to 192F or so if I kept measuring.

I'm not sure but plan to find out what temp the fans cut on at. I can't recall if it is the same as the thermostat or close to it or if it is a good bit lower. I'll check on that in a bit tho.

I also measured several other places on the car. That 192F was the highest I could find except right around the exhaust manifold and such. The cam/valve cover measured about 160 to 170F. I plan to do some more measurements over the next few days and will post them if anyone is interested.

I might add, my brother runs straight antifreeze in his little Honda. It's a older carburetor model. He has done that for a long time. Anyway, no problems but he did watch his temp gauge when he first started doing this.

Also, I run Morey's oil stabilizer in my oil. That is some slippery stuff. It is also sticky. It's sort of like that Lucas stuff but better in my opinion. It is thick so I also add some Marvel Mystery Oil which sort of thins it back down a bit and keeps the engine clean on the inside. Anyway, Morey's helps reduce friction which leads to lower temps. It is going to get to 192F either way since the computer will see to that but still, it produces less heat. Another way to say this, it will take longer to produce the same heat as it would without Morey's. That said, I did go for years without Morey's in it since I had never heard of it. My brother who was a mechanic introduced me to the stuff. I will say this, in the winter time, my heater is nothing to write home about. It does warm up but it takes a while. Morey's was made for large trucks but also works fine in gas engines too.

Let me know if you are interested in additional info. Thanks MUCH for your replies.

 

Talk about innovative, LOL I run water wetter in my coolant/water mix.