engine overheats when speed is constant 130kph

[goose]

Hi Guys,

Need some advise here. I have a 1995 honda civic lx. I just had a trip with my friends last weekend. When we were chasing each other at a constant speed of 130+kph, my car overheated even there is water. The water plug got busted when my car overheated. My question is, why did my car overheats when I speed up to 130kph, I don't know if this is the limit of my car but it should not overheat if it reaches its fastest speed, Am I right? Any suggestions that I can do to my engine to avoid overheating.

Thanks again.
Goose

[PrimeTimeV6]

Maybe your freeze plugs just rotted out. Did you realize it was overheating before or after the plug went? But at normal speeds did it get hot?

[goose]

I did not notice the temp gauge when I was speeding at first, When the car stopped, that was the time that I saw the gauge is at the very peek. When I opened the hood, I saw the lower part of the engine was wet, it was then that I notice that the water plug was busted.

When I replaced the water plug, at speed below or equal to 120kph,my temperature is constant which is below the middle line of the temperature gauge, when I speed it up to 130kph for about 1-2 minutes, the temperature rises up above the middle line of the gauge, that's the time that I tend to slowdown so I will not overheat again.

When you referred to freeze plugs, are you referring to the water plug? I saw on a store that there is a Antifreeze coolant, do I need to buy this stuff?

[PrimeTimeV6]

Straight water will keep it cooler than using antifreeze mix. but antifreeze helps in winter months where you are below freezing temperatures.
Freeze plugs, water plugs are the same thing. Are your fans working properly and is the radiator full? It is possible that you have air in the system due to a small leak. You may also need to flush out the coolant system or need a new radiator. There are a list of thing that it could be.

[8695Beaters]

^^^I agree with everything Prime Time said. Your radiator may also be a bit clogged with age. There are some additives you can use to flush out the system (not a bad idea either). Also try Redline's Water Wetter. That works wonders, I've tried it.

[splink48]

I believe that antifreeze (mixed with water) has a higher boiling point than water alone (along with a lower boiling point). If you just run water and it gets to a boils (which only takes 212 degrees), it increases the pressure dramatically which could have blown the freeze plug out.

Another thing you may want to consider is the radiator cap. In your car, it regulates the pressure of the cooling system. If its shot, then it can wreak havoc on your system.

[goose]

The fan is working properly. I've been thinking about what you guys said on the radiator. My radiator is made of metal, not the stock radiator which is plastic. Is the water on the radiator and the reserve should be at constant amount. I usually put water on the reservior in the morning use the car to go to office, but when I check the tank reserve, its empty or has a very low level. Should this be happenning? or should the water level be at constant level. I was thinking that the water is evaporating because of the heat, but should it be like that? should I replace my radiator with the stock plastic radiator? And is the radiator flush harmless?

Thanks again.

[goose]

Additional question:
What should be the specs of the radiator cap? Is the effect on the radiator cap very significant?

[splink48]

You've got a 16lb cap on yours. What that means is the cap maintains 16 lbs of pressure on your cooling system. The pressure helps maintain the temp of the coolant as well as the amount of coolant in the system (ie, when the coolant is hot, it expands, before it can blow something up, the cap allows enough coolant to enter the coolant recovery jug and bring the pressure back down to 16 lbs).

As far as putting water in the car every morning, if you put some in once, then checked it later to find out it was gone, then you're losing some. Do you see any smoke coming out of the exhaust? Or to be more obvious, do you have any leaks in your motor?

[goose]

Oh, that's what the cap is for. Glad to know it, i will check if my radiator cap is working, but how do I test it?
About the water being gone, I don't see smoke coming from my muffler and I dont see any leaks in the engine. I usually check under the car if there are any substance dripping but I didn't find any. Do you think that the problem is on my radiator cap?