The Engine Explained

The engine is the heart of your car, but instead of pumping blood, the engine pumps air and fuel. The engines main function is to convert air and fuel into rotary motion so it can drive the wheels of the car. How does it do that ??.... Well let's start with a cutaway of the engine and see all the major parts then we will get into the actual mechanics. Pistons: Most common engines have 4, 6, or 8 pistons, which move up and down in the cylinders. On the upper side of the piston is what is called the combustion chamber where the fuel and air mix before ignited. On the other side is the crankcase, which is full of oil. Pistons have rings which serve to keep the oil out of the combustion chamber and the fuel and air out of the oil. Crankshaft: The crankshaft is connected to the pistons via a connecting rod. As the piston moves up and down in the cylinder it rotates the crankshaft and converts the straight line motion into rotary motion. Valve train: The valve train consists of valves, rocker arms, pushrods, lifters, and the camshaft. (shown in above picture in blue, yellow, and green) The valve train’s only job is that of a traffic cop. It lets air and fuel in and out of the engine at the proper time. The timing is controlled by the camshaft, which is synchronized to the crankshaft by a chain or belt. Now that we have a general overview of the parts involved let's talk about what happens. Most automotive engine today are 4-stroke (or 4-cycle) engines, meaning they have four distinct events which make up the cycle. · Intake stroke: The camshaft opens the intake valve and the piston moves down the cylinder. This creates vacuum and sucks in air and fuel into the combustion chamber above the piston. · Compression stroke: As the piston starts moving back up the cylinder the intake valve closes and seals off the combustion chamber. The causes the air and fuel to compress. · Power stroke: As the fuel is compressed and the piston nears the top of the cylinder the spark plug fires and ignites the fuel and air. This explosion pushes the piston back down the cylinder and drives the crankshaft. · Exhaust stroke: After the piston reaches the bottom of the cylinder, the exhaust valve opens and the gasses left over from the fuel and air are sent out to the exhaust system. Put these four events together in the above order and you have a complete cycle. Are you asleep yet? That's enough theory, let's talk about the real world and problems you might encounter with the above mentioned parts. Pistons: Remember I talked about the rings, which seal the combustion chamber from the crankcase. The rings over time tend to wear out. When they wear they allow the fuel and air to enter into the oil and dilute it. This dilution reduces the oils ability to lubricate your engine and can cause premature wear. Also if the rings wear down they can allow oil from the crankcase to enter the combustion chambers. This will result in oil being burned and exiting your tailpipe as grayish/white smoke. If your car spews grayish white smoke and it does not go stop in the first few minutes after start-up you might have warn rings. If the smoke goes away after start-up look to the valve train section. Crankshaft: The crankshaft rides on bearings, which can wear down over time. The bearings support the crankshaft and also the rods, which connect the pistons to the crankshaft. A loud medium pitched knocking noise in the engine points to warn bearings most of the time. This is usually a costly repair and involves removing the crankshaft and either machining the surface where the bearings ride, or replacing the entire crankshaft. To prevent this type of problem, use a high quality oil, change your oil at suggested intervals (3 months or 3000 miles is a safe number) and always maintain your oil level between oil changes. Valve train: Remember the oil smoke problem mentioned above in the piston sections. If your car only smokes grayish/white smoke at start-up you may have leaking valve seals. Valve seals keep oil from above the valve from leaking into the combustion chamber. When they wear, they can allow oil to seep into the combustion chamber and collect there until your start the engine again. You generally do not get oil leaking past the valve seals while the engine is running since the seals expand with the heat of the engine and plug the leak. Another common problem is the timing chain or belt will slip or even break causing the cam shaft to stop rotating. Remember the camshaft tells the valves when to open and if it stops spinning then the valves stop opening and closing. No valve moving, no engine running :-) A term you will here when talking about timing chains and belts is "interference engine". When an engine is an "interference engine" the pistons and valves are so close together that if the valves were to stop moving (broken belt or chain) and the crankshaft kept spinning they would crash into the piston. (that's the interference) This crash tends to do bad things to an engine, breaking valve, bending pushrods, and even cracking pistons. This is why most manufacturers recommend changing the timing chain or belt every 60,000 miles. Timing belts dry out, stretch and deteriorate over time so even if you do not have 60,000 miles on the car think about changing the belt after it's 6 years old. Preventive Maintenance: · Change your oil regularly. · Give your engine a chance to warm up before driving if possible. Let the oil get into all parts of the engine before driving. This is even more critical in cooler temperatures when the oil is cold and sluggish. · Change your timing belt or chain at your manufacturer's recommended interval. · void "snake oil" additives advertised on late night TV. Regular oil changes and good maintenance habits will keep your engine running it's best. · If you have a turbo charged engine, give the engine a minute or two cool down before turning it off. This cool down period allows oil to circulate and cool down the bearings. If you shut off the engine immediately after hard driving, the oil can gum up around the hot bearings and create problems down the road. What to discuss with your mechanic: · If you have to replace your engine, discuss the benefits of buying used versus new. If you plan on keeping your car for some time, a new engine might be the best bet. Sometimes new engines are not much more expensive than rebuilt ones, and offer the best solution. · When trying to diagnose engine noises, be as descriptive as possible. Take note to when the noise occurs; at what throttle position, and when the noise started occurring. Sometimes changing the weight of oil being used can cause a new noise to crop up. Make sure you mechanic knows if you changed oil brands or weight recently.

Getting Your Car Ready For Summer Driving

We always seem to make sure our cars are ready for the winter, right?But what about during the summer? Believe it or not, the heat takes its toll on your car, too, so it’s important to keep your car serviced.Periodic maintenance on your car will save you tremendous hassle in the long run. Your vehicle should last longer and command a higher resale price, too! I made it a point to get my car serviced according to the dealer’s schedule, and when I traded it in, I got far more than I expected due to the stellar condition of the engine.Now I know this isn’t bedtime reading, but the owner’s manual can be your best friend – assuming you read it! At least take a look-through periodically. How about while you’re waiting to get your oil changed?Follow the manufacturer's recommended service schedules. This could save you a major breakdown.Have the air conditioning system looked over by a qualified technician. A check up here can save you a huge bill later.The greatest cause of summer breakdowns is overheating. Prevent this problem by making sure the cooling system is flushed and refilled as recommended.Have your car’s belts, clamps, and hoses checked by a technician. This only takes a few minutes and is usually inexpensive.Change your oil and oil filter every 3,000 miles or four times a year.Replace air and fuel filters as recommended.Get plenty of windshield washer solvent – we have a tendency to use a lot of this in the winter, so your fluids may be low.Tires should be rotated every 5000 miles or so.Check the spare tire to make sure it’s inflated properly. Also, make sure you have a jack along with it!Transmission troubles equal money troubles equal emotional troubles! Have your transmission serviced periodically, and prevent big-time repair bills.If you notice that your brakes are less efficient, get them checked out right away.Have your battery checked periodically to see how much life it has left!Inspect all lights and bulbs to make sure they’re working.Carry a first aid kit, flares, jumper cables, a flashlight, and a cell phone.There you go – a simple list to keep your car in great running shape. Remember, your car needs to be maintained and checked over even in the summer.Taking care of your car takes only a few minutes each month, and pays you big dividends for the life of your vehicle!

How to Get More for Your Money at the Gas Pump

Gas prices have been spiraling out of control for months, and there is no end in sight. Increased gas prices do not just hit you when you fill up your tank though. Just think about it for a minute and you will realize how many other ways rising oil and gas prices will cost you. The price of airline travel and shipping services are likely to rise, as is the cost of many other goods as retailers are forced to pay more for delivery.You may even see your property taxes increase as towns have to pay more to keep their police cars, fire engines, and garbage trucks on the road. During times like these it is important to get as much bang for you buck at the gas pump as possible.So how can I save money on gas?While there is little you can do about the market price of a barrel of oil, there are ways to keep down your own personal costs at the gas pump. Here are some suggestions:Don't pay extra for premium gas if you don't need it. Consult your owners manual and stick to the recommended octane. Most cars run just fine on regular unleaded gas and you will get no extra performance by using premium gas. Shop around. Keep a watchful eye and you'll be surprised at how much prices can vary from one gas station to the next. I've seen differences of eight to ten cents per gallon between gas stations directly across the street from one another. Seems like a small difference but it adds up over time.Schedule your errands to minimize drive time, or if possible walk. Travel light. Keeping your car and backseat loaded down wastes fuel as it requires more energy to move a heavier car. Take only the essentials (a spare tire, first-aid kit, jumper cables, etc.) with you. Slow down. The faster you drive the fewer the miles you will get per gallon.Drive steady. Avoid quick stops and accelerations that waste fuel. Anticipate braking ahead of time and ease onto the gas pedal rather than flooring it. Maintenance is key. Keeping your engine tuned and tires inflated can make a difference in your fuel consumption. Under-inflated tires create drag which causes the engine to use more energy to propel the car. Plus, it is unsafe to drive on tires that have too little or too air in them. If you are in the market for a new car, consider models that are more fuel efficient. Use the air conditioner judiciously. There are two schools of thought on this one. The first says you will burn less fuel with the windows down and the AC off. The second says that driving with the windows open creates drag, which wastes more fuel than would be used if the AC was on and the windows up. So which one is true? Well...both of them really. The car will consume more fuel with the air conditioner on and the windows down, up to about 45-50 miles per hour. As you drive faster, the drag caused my the open windows will actually cause high fuel consumption. So the rule of thumb is this: keep the AC off and the windows down when you are cruising around town and on city streets. Once you reach the highway or about 50 mph, roll up the windows and turn the on the AC. Using these tips will help you save money on gas. While you may not notice a huge difference with each fill up, the savings will compound with each fresh tank.