Automotive engines use a coil to produce a high voltage spike to fire a spark plug that ignites the air/fuel mixture in the combustion chamber. If a fuel mixture fails to ignite in a cylinder, that causes a misfire which will usually be noticed by an engine’s PCM; triggering a fault code. Mild occasional misfires aren’t … Read more
The blower motor resistor is in charge of regulating the speed of the blower motor. It can do this in one of the two ways; both are common in modern vehicles. The classic blower motor resistor is a block with various resistors inside it that will switch power to the blower through different resistors based … Read more
The sensor is a pretty simple electrical device which has a resistor built in that is sensitive to temperature. It has a plug on one end and a probe on the other end that extends into the coolant. It is either screwed or pressed into position and usually fairly easy to replace. Sensor diagnosis is … Read more
Most modern engines use a variable valve timing system to finely control the timing of the opening and closing of intake and exhaust valves. This ensures the best emissions and efficiency under a variety of conditions. Usually, this is done with actuators on the front of the camshafts which are operated by oil pressure. The … Read more
One way to describe an internal combustion engine is to think of it as a big air pump. It sucks in air, adds fuel, compresses and ignites the mixture, then, pushes the air out the exhaust. The main thing controlling the speed and power of the engine operation is how much air is allowed in. … Read more
Every automobile engine generates a great deal of heat which is carried by the coolant system to the radiator where heat is drawn off. This sits in a position where it receives good airflow. In order to transfer heat efficiently, a radiator has a core made from many fine passages of thin metals which are … Read more
Some engines rely on a single chain to operate overhead cams, some rely on two or three chains, and some have more than that. In any case, all are directly timed to the crankshaft. There is a fixed order to disassembly and reassembly, and there are marks to get everything set up correctly. In order … Read more
A starter is essentially a strong electric motor that spins up the engine of a vehicle; allowing it to start its fuel-powered operation. It draws a great deal of current from the battery to turn the engine. As with any high-current electrical device, reliable switching of power is difficult. Starter motors almost always have an … Read more
All modern automobile engines are “water-cooled” which means they use circulating fluid to carry heat from the engine to a radiator where it is cooled and circulated back. Coolant is about 50% water and the balance is made up of a variety of chemicals and additives. These lower the freezing point, improve the heat absorption … Read more
On any automobile engine, one of the basic engineering challenges is how to transfer the rotating force from the crankshaft to the valve train. This is so that the valves open and close at exactly the correct times relative to the motion of the pistons. On most older-style engines, this is done by a camshaft … Read more