 |
|
|
Modifying the cooling system won't really improve gas mileage or horsepower. In theory a hotter car runs more efficiently. However, engine parts, oil, and gaskets will begin to fail at higher temperatures. The use of colder thermostats isn't recommended unless you really know what you're doing with a turbo or high compression custom engine. This page is more about the Do's and Don'ts of engine cooling systems and how it works. The cooling system is there to keep the engine at a steady operating temperature that is about 210F (99C). Without the cooling system the engine temperature would continue to rise until the engine breaks apart. The cooling system is comprised of a heat source (the engine) that needs to be cooled, a water pump, a thermostat, a radiator, hoses, an overflow tank, and coolant. The engine creates heat and transfers that heat to the coolant that flows through passages inside the engine. The water pump moves coolant from the engine to the radiator. As the coolant passes through the radiator the ambient air brings the temperature of the coolant down. The cooled coolant is then pumped back into the engine to absorb more heat.
The purpose of the thermostat is to open when the temperature of the coolant reaches the engine's operating temperature. When the car is cold the thermostat is closed to prevent the coolant from flowing. This makes the engine retain heat so it can reach operating temperature quickly. To test a thermostat put it in a pot of water and heat the water. Measure the temperature of the water when the thermostat opens. If it doesn't open at the temperature printed on the thermostat throw it out. The hot coolant is pressurized inside the engine.
The radiator cap specifies the pressure of the cooling system. Excess
coolant is bled off into the overflow tank. Change water pumps every time the timing belt or timing chain is replaced, which is about every 100,000 miles for most cars
DON'Ts Do NOT open the radiator cap when the engine is hot. The coolant is about 210 F and pressurized! Boiling hot water will squirt out in all directions and cause severe burns. Do NOT drive a car that is overheating! If the car
is overheating, pull over to the nearest parking lot and wait two
hours for it to cool down before driving it again.
Do NOT ever use hose water, or tap water, or drinking water, or mineral water! Use ONLY distilled water in the cooling system. Minerals in the cooling system corrode the aluminum in the engine head and radiator. This causes radiator leaks. The picture above shows mineral buildup on the water pump and water pump gasket. Does your car make gurgle noises when you turn it off? You've got air in the coolant. With that much air, the coolant can't flow. The car will overheat. Wait till the car cools down (about two hours) and open the radiator cap. Pour in some distilled water and antifreeze. Warm the car up till the cooling fans come on and turn it off. Let the car cool down for two hours and then fill it again with distilled water and coolant. You may have to pinch the hoses to remove trapped air bubbles. Repeat the process until the gurgle noises go away. Do NOT dump used coolant down the drain! It is a sweet tasting poison that can kill pets and wildlife.
DO's I recommend changing the coolant every 15,000 miles or so, even for extended drain interval coolant. As coolant ages it becomes acidic and can even hold an electrical charge. This charge can change the voltage of the engine temperature sensor giving a false reading to the engine computer. Old acidic coolant destroys the aluminum in the radiator and engine head. After changing the coolant the cooling fan will run for shorter periods of time. Go ahead and clock the cooling fan run time before and after a coolant change. The difference can be measured in minutes. This is because the new coolant is doing its job more efficiently. Use the type coolant that the car manufacturer recommends! Chrysler’s use green stuff, GM uses orange stuff, and some Euro cars use blue stuff. Don’t ever mix it up! Zerex is a Valvoline product that I use and recommend. Mix the antifreeze and distilled water in a ratio that's appropriate for the season and climate. This should be outlined on the back of the antifreeze container or the car's service manual. Not sure how much coolant to put in? Want to mix a 60/40? Pour in 1 quart of antifreeze and 2/3 quart of distilled water. Repeat this until its full. I recommend using Prestone® Super Radiator Anti-Rust additive and Water Wetter. I also recommend flushing the coolant system several times with distilled water to clear all the rust out of the system.
Problems If there are grey globs floating about in the coolant then that mean that engine oil is leaking into the coolant. This is usually the result of a head gasket failure. Headgaskets should be changed with timing belts every 100,000 miles. Some manufacturers may recommend changing the headgasket at longer intervals, but I wouldn't risk it. Conversely, if the grey globs are in the oil, the same failure is occurring. Another strange and rare problem is a failure in the temperature sensor. Old acidic coolant eats through the sensor and can leak through the wire and to the engine computer causing electrical shorts. I said it was rare.
Improved Maintenance Topics:
Copyright 2008 - 2009. Efficient-Mileage.com. All rights reserved. |
