On the car you buy, used or new, the engine and coolant system is really a simple boiler Car engines operate on the same principal as a locomotive steam engine boiler. The difference is that instead of heating the water (coolant) with firewood or coal, the hot engine in the car provides the heat because ignition is taking place inside of its cylinders at 2,000oF. This is true of all cars whether or not you make a car comparison between different models before buying one.

Modern car engine coolant systems are operated at about 220o F; which is above the 212oF that water boils at sea level. As the coolant temperate exceeds 212oF, it begins to turn to steam and the pressure rises. That means empty volumes above the coolant level will be filled with pressurized “steam”. The hot engine continues to add heat to the coolant until the coolant reaches about 220oF operating temperature. The water pump continually moves the coolant around the engine cylinder block until the coolant temperature reaches this operating temperature.

Now the radiator starts to do its job At the operating temperature a sensitive valve opens in the radiator, allowing the hot coolant to be pumped into the radiator where the air being pushed out of the way by the moving car will hopefully be enough to continually maintain its system operating temperature at 220oF. But remember, the pressure in the entire coolant system now is greater than the outside air we are breathing. That means the coolant wants to get out, and it will, through any tiny crack it can find. Eventually some will get out, and the coolant supply will decrease. If it decreases enough, the engine cannot be cooled enough and engine parts will expand and “seize”, ruining the engine.

How to avoid an overheated engine To avoid this problem, the engine system has a clever makeup coolant tank connected to it through a check valve.

What’s a check valve? Here’s how to make one in your kitchen and see how one works. Take a throwaway plastic cup and make a round hole in its bottom. Take a round marble bigger than the hole and dump a lot of kitchen cleanser around the hole in the cup; then take the marble and rub it around the hole until it really make a nice round seat in the hole.

Now fill the cup half full of water. If you did a good job no water will sneak around the marble and drip out of the bottom of the cup. Hooray!

Now take your finger and slightly lift up the marble from beneath the cup, raising it slightly above the seat you created by scrubbing with cleanser (do it over the sink) and water will leak out on your finger.

You have just made a one-way check valve. The coolant makeup tank has such a check valve in it but also has a spring to keep the ball pressed down on the valve seat. That side is toward the radiator, so that coolant under pressure cannot push back into the coolant makeup tank, which is under atmospheric pressure.

What happens when the car cools down? When the coolant in the engine and radiator cools down to below boiling temperature, the steam that was above the liquid coolant will condense (turn back to water or coolant) and the coolant system will have a pressure that is less than the outside pressure of the air you are breathing………………a vacuum will form in the coolant system. Now it gets exciting.

The cycle reverses Whereas while the engine was running, the hot coolant wanted to get out; but now that it has cooled down, the outside pressure (what you’re breathing) is more than the pressure in the coolant system (that includes the entire engine, the radiator and all the connecting hoses) and now the engine and radiator combined want to suck something in, namely more coolant.

When this happens, the check value in the coolant is opened by atmospheric pressure, overcoming the spring on the check valve, and fresh makeup coolant is sucked into the radiator, thereby replenishing coolant to normal.

So every time you stop and car and let the engine cool down, the whole system automatically restores the coolant level to normal without any driver assistance. Magic? You bet.

Maintenance Always keep the coolant makeup reservoir at least half full. It’s usually under the hood in a semi-transparent plastic tank, fastened against the inside of one of the front fenders, and the coolant is always colored (in winter) so the level can be easily monitored.

Something to think about: The hot air you arrange to heat your feet, inside the car, is really inside air blowing across a very small radiator, just like the big radiator under the hood. This foot-warmer radiator too goes through the same pressure increases and decreases, as does the whole coolant system, since it is part of it.

So don’t ever kick it with a sharp toe if you’re mad at it while the engine is running, or you will get a free bath of really, really hot, coolant water sprayed all over your feet.

Article author Ralph Hoffmann majored in Applied Math at the Univ. of Wis. His venture capital and business experience encouraged him to develop Internet site http://www.AutoTruckData.com/Form_13.htm
It offers a software program providing data and facts, for any given monthly budget, of all cars, Vans, SUV’s, or Light trucks available from all manufacturers, whether leasing or buying, and saves hours of Internet surfing. It shows how to make an offer based on a Dealer’s profit

Combing the strengths and elements of Chevy’s original utility vehicle, the 1949 Chevy Suburban, and the company’s current roadster pickup, the Chevy SSR, the 2006 Chevy HHR holds a distinct design. The 2006 Chevy HHR is a crossover vehicle that has combined both a small sedan as well as a small sport utility vehicle. This kind of combination has made this vehicle unique in style and still highly functional.

This vehicle is built on the same solid platform that the Chevy Cobalt also uses. Lori Queen, GM vehicle line’s executive for small cars, states, “The HHR is what you want it to be, whether you’re hauling band equipment around the country or hauling your friends across town. With its unmistakable styling and innovative features, the HHR is further proof that there is a new spirit at Chevrolet.”

The 2006 Chevy HHR comes available in two trim levels. These are comprised of the more basic LS and the LT model which offers more perks. Both of these models are powered by a 2.2 liter engine with four cylinders. This engine has the capacity to produce 140 horsepower and some 150 pound feet of torque. Standard for this vehicle is a five speed manual transmission as well as a four speed automatic. The 2006 Chevy HHR boasts an overall length of 174.5 inches and some 63 cubic feet of cargo capacity. This vehicle can take in into its cabin a maximum of five passengers.

Standard features for the 2006 Chevy HHR include air conditioning, power windows, power door locks, a CD stereo with six speakers, a remote keyless entry, an MP3 player, a six-way power seat with power lumbar, a satin exterior finish, the anti-lock braking system, traction control, fog lamps, a steering wheel and shifter wrapped in leather, the Pioneer sound system with subwoofer, 17 inch of wheels, and heated leather seats. Other features for the 2006 Chevy HHR include a driver information center, adjustable cargo configurations, a power sunroof, the OnStar system, an XM satellite radio, and a remote start.

There are other surprises that the 2006 Chevy HHR holds in store for owners and users. This vehicle’s front passenger seat can actually fold flat so as to extend the total load length from the liftgate to the instrument panel. The center armrest of the front seats is integrated into the seat back frame so much so that it can be pivoted into a stowed position. Providing a continuous flat load floor are the rear seats when they are folded down. Concealed under the floor is a recess bin some five inches deep. This is for the spare tire. The 2006 Chevy HHR also holds driver and front passenger frontal air bags as well as front safety belt pretensioners to provide complete safety during crashes and collisions.

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