At some point, mechanics, car enthusiasts, or people who just like to dabble in do-it-yourself auto repair, might need to know a thing or two about diesel engine parts. For those who already know quite a bit about gasoline engines, how they function, and what their major parts are, you will be glad to know that several diesel engine parts are very similar. In fact, many diesel engine parts are more or less the same as their gasoline engine counterparts – they are just a bit sturdier and hardier. As far as diesel engine parts that you will not see (as compared to a gasoline engine), most notably absent will be spark plugs and all the other components of the spark ignition system used in petrol engines.
For you newly training diesel mechanics or diesel engine car owners, here is a general guide to some of the main diesel engine parts that you will need to be familiar with.
- Injection Fuel Pump. This diesel engine part is in charge of pumping fuel in the cylinders of a diesel engine. The gears or a toothed belt (like the timing belt) drive the camshaft. The camshaft indirectly drives the pump. The pump rotates at approximately half the speed of the crankshift (in a four-stroke engine).
- Camshaft. This diesel engine part is made up of two things, a “cam” and a “shaft”. When a shaft is attached to a cam or when they are integrated, it is referred to as a camshaft. The camshaft pushes against valves which open as the camshaft rotates. Springs on the valves help them go back to a closed position. This is a very important process in the diesel engine. A faulty camshaft can greatly reduce the engine’s performance.
- Crankshaft. This is also sometimes just referred to as the ‘crank’. It is the part of a diesel engine that turns linear piston motion into rotation. To convert the motion into rotation, the crankshaft has “crankpins” (surfaces offset from that of the crankshaft) to which the ends of connecting rods from each cylinder attach. It is typically connected to a flywheel and sometimes is connected to either a torsional or vibrational damper at the opposing end.
- Rocker Arm. This is a lever that swings back and forth. It conveys radial movement from the cam into linear movement at the poppet valve. This movement opens the poppet valve. One end of the Rocker Arm is raised and lowered by the rotating lobes of the camshaft. Meanwhile, the opposite end acts on the valve stem. When the camshaft lobe lifts up the outside of the Rocker Arm, the inside presses down on the valve stem, opening the valve. When the outside of the arm returns to the original position (as the camshift rotates), the inside of the arm rises up and causes the valve spring to close the giver. The drive cam is driven by the camshaft which pushes the rocker arm up and down around the trunnion pin.
- Diesel Oil Pump. This is another diesel engine part that works with the camshaft of the engine. The main function of the diesel oil pump is to take oil back to its source when pressure goes above the preset limit. Most diesel oil pumps have a spring-loaded pressure relief valve. The pressure relief valve is key in the functioning of the oil pump.
- Fuel Filter. A diesel engine fuel filter is precisely what the name implies. Most internal combustion engines nowadays have them. Their main purpose is to keep particles (such as dust, dirt, paint, rust, etc.) out of the fuel. If the fuel filter fails, this means a lot of damage for the injection fuel pump and the entire fuel system. Effective fuel filters is one of the diesel engine parts that can instantly affect efficiency – if the fuel is contaminated, it won’t burn as efficiently as it should.
As a final note, replacing diesel engine parts with traditional iron ones will maximize the life of the car or equipment you are repairing. There have been some moves toward manufacturing aluminum diesel engine parts, but these aren’t as durable as the original iron ones.