Engineworld

What is the Camshaft Seal all about? Like the crankshaft, the camshaft is an essential component of the combustion process that moves your car down the road. Its motion is responsible for instigating valve movement, which regulates the air/fuel mixture that fuels the “big bang.” The camshaft uses lobes (called cams) to push against and open the valves as the camshaft rotates (springs on the valves return them to their closed position) in sync with the pistons. Note: Both valves are closed during compression and combustion so that the combustion chamber is sealed. The camshaft seal fits between the camshaft and the cylinder head, sealing the camshaft between the top of the head and the valve cover. Like all of an engine’s internal moving parts, the camshaft must be well lubricated, essentially submerged in oil, to do its job properly. Without the camshaft seal, this lubricating oil would leak out of the engine block, befouling the engine bay and putting the engine’s internal comp...

What is the Automatic Timing Advance Unit all about? Gasoline and diesel engines may seem similar, and they do work on the same basic principle of combustion, but they’re very different. They require significantly different steps taken to control fuel flow throughout engine operation. Diesel fuel takes longer to combust than gasoline, and in an operating engine, combustion can take place well after the timing hits top dead center (TDC). If this occurs, then it creates lag, which has a negative impact on engine performance. To combat lag, diesel must be injected before the timing reaches TDC to provide enough time for combustion to take place. This job is handled by the automatic timing advance unit. Essentially, the unit ensures that no matter what speed the engine is operating, fuel is injected with ample time for combustion to occur before TDC is reached. The automatic timing advance unit should be located on the fuel pump itself, and is operated by the engine's primary d...

Automatic Shutdown Relay Replacement What is the Automatic Shutdown Relay all about? When you turn the key for your ignition to start, many different things happen. The fuel pump turns on, sending gas from the tank, through the lines, to the injectors. The battery sends voltage to the ignition system, which creates a spark, igniting fuel vapor and starting your engine. However, if the automatic shutdown relay (ASD) is not working, none of this will happen. The automatic shutdown relay controls the power that is supplied to the ignition, the fuel pump, and the injectors, as well as other components. It is only activated for a few seconds during cranking, and is then turned off. Depending on the make and model in question, the automatic shutdown relay could be located under the hood, under the dash, or in another position. As with any other electrical component, your automatic shutdown relay is subject to wear and tear, and frequent stopping and starting of the engine will ex...

What is the Alternator all about? The alternator is the component that charges the battery in your car. When you use electrical components in your car (stereo, lights, etc.), the battery loses power. The alternator recharges the battery, replenishing the lost battery power. The alternator is located in the engine compartment. If the alternator is not working properly, your car will only stay running for as long as the battery has power stored. Once the battery loses power, your car will not start. Normally, a malfunctioning alternator will turn on the battery warning light or will have a low volt gauge reading. Keep in mind: The mechanic should check the entire charging system before installing a new alternator, including checking battery cables for corrosion and the condition of the battery. MY recommendation: Ask your mechanic to inspect the condition of the charging system during every major service. Mechanic should also clean and tighten the battery cables ...

Car Air Pump Check Valve  What is the Air Pump Check Valve all about? In a secondary air injection system, air must be injected into the exhaust system, but exhaust fumes must not be able to escape. This is accomplished by using a one-way air pump check valve. Think of it as a one-way street -- air can enter, but exhaust gases can't leave. These secondary injection systems are used to ensure a fuller burn of spent exhaust gases, which both improves fuel economy and eliminates pollution from the vehicle exhaust. It’s an important part of your emissions system. Generally, the air pump check valve is mounted near the top passenger side of the engine, although this can vary. Some vehicles have more than one check valve, as well. Over time, the air pump check valve is subject to not only high heat, but also other forms of damage. It can deteriorate and degrade. While there is no set lifespan for these components, they can and do fail. Keep in mind: The air pump check v...

What is the Air Diverter Valve all about? Most vehicles today use some sort of secondary air injection system to help control emissions. All use some form of air pump, whether electric or belt driven, and all inject air into the exhaust stream to enhance re-burning for emissions control. Some use an air pump check valve to keep exhaust in the system but allow air to be pumped in, but others use an air diverter valve. This serves the same purpose and works in essentially the same way. The air diverter valve is operated by the air bypass solenoid, and opens to allow air into the exhaust system, but closes to prevent exhaust from escaping. Keep in mind: The air diverter valve is not inspected during any maintenance or service unless there’s a problem. Over time and through normal use, the valve can wear and eventually fail. Many pump assemblies include the air diverter valve and must be replaced together. My  recommendation: Without a functioning secondary in...

Oil Change Service  What is an oil change all about? Engine oil is the lifeblood of the engine. The oil resides in the oil pan, which is under the car attached to the bottom of the engine. All internal (moving) parts of the engine need to be lubricated by the engine oil. Inadequate lubrication will cause the parts to wear out faster and eventually lead to engine failure. An oil filter keeps the oil clean and free of debris. If the filter is not replaced on a regular basis, it will get clogged and will not be able to pass oil into the engine. Keep in mind: When the oil is changed you should always replace the oil filter. Replacement oil should always match the required specifications for your vehicle. After your oil has been changed, it’s a good idea to run the vehicle for a few minutes to make sure that there are no leaks. How it's done: Remove and replace engine oil and filter. Check the condition of all fluids. Perform basic safety inspection. Star...