The basic law for trouble with any equipment is, if there is a part that is vital for its functioning, then it’s usually that part that is giving you trouble. In an engine, the basic problems may occur due to problems with the fuel mix, lack of spark or lack of compression. But in no way is engine trouble limited to these three. There are millions of other parts that may be giving you a headache, but these are the fundamental parts of the engine, and thus, most problems boil down to these three.
Fuel mixing problems
Fuel is the most important stuff that makes your car what it is. Without it, many of the components are just that – plain metal and plastic. But when air fuel mixture isn’t being supplied to the cylinders, you have a problem. This may happen due to several reasons.
1. There is no fuel.
This is the most obvious reason. There is no fuel, so, there is no combustion. So, your car does not move. Simple.
2. The intake valve is clogged.
If the air intake is clogged, then air and fuel mixing does not take place properly in the carburetor. This results in too much fuel, too less air. The cylinders have nearly nothing to compress, and they fail to run.
3. The fuel system is faulty
If the air intake is working properly, it follows logically that the next problem might lie with the fuel intake. If the fuel intake is clogged, you do not have fuel in the cylinders, resulting in too much air, and there’s absolutely nothing to burn in the cylinder.
4. Presence of certain impurities in fuel
The main enemy of combustion is moisture. It decreases the heat produced during combustion, it makes the fuel difficult to burn, and it decreases engine efficiency by a lot. Sometimes though, when too much water is present in the fuel, the fuel simply refuses to burn.
Compression causes the air to get pressurised. Moreover, the end of the compression stroke triggers the combustion stroke, the most important of the four strokes. If the gas is not compressed properly, then combustion might not take place so efficiently, resulting in your car failing to run properly. Compression troubles can be caused by the following.
1. Worn out piston rings
Piston rings go on the top of the pistons, ensuring a good seal between the piston and the cylinder. A piston ring which is worn out can cause oil from the sump to enter the cylinder, or fuel from the cylinder to enter the sump. The first case causes a lack of lubrication and the second case causes no spark to be created.
2. Faulty intake and exhaust valves
Intake and exhaust valves allow the fuel and air mixture to come in and exhaust to go out. During the compression stroke, the valves have to be closed completely. If not, the mixture escapes during the compression stroke and thus, combustion does not take place.
3. “Holes” in the cylinder
The cylinder head is the part of the cylinder which houses the exhaust and intake valves, and the spark plug. A seal is created between the cylinder head and the cylinder to ensure that the cylinder is leak proof. If this seal is faulty, then there are “holes” created which leak and thus compression does not take place.
The spark created by the spark plug ignites the air fuel mixture, thus pushing the piston down and producing power. If the spark is not created or is weak, then combustion does not take place. The following are some reasons for a non existent spark.
1. Faulty spark plug wiring
One of the more obvious faults. The wiring to the spark plug might become faulty for a number of reasons, and without an electric signal, the spark cannot be produced.
2. Faulty mechanism
The spark plug is a device which produces a high voltage so that the spark jumps a gap consisting of the air fuel mixture, thus heating it and producing combustion. If this mechanism fails, then the spark plug just won’t work.
3. Wrong timing
If the sparking occurs too early or too late, then, at the very least, there will be improper combustion which will cause the engine to malfunction. It will also cause increased fuel consumption and emissions.
By no means are auto problems limited to those described above. There are several more things that can go wrong with your car. In fact, the list here is a lot longer that that described above. Some more things that can go wrong with your car are given below. They may not have their own section in this article, but some of these are just as serious.
1. Dead battery
The battery is used to provide starting juice for the engine. Without it, the ignition system won’t work, and the engine will refuse to run.
2. Worn crankshaft
The crankshaft transmits the power produced by combustion to other parts of the car. If the crankshaft’s lubrication is faulty, or if it does not rotate for some reason, then your car won’t move.
3. Faulty valve timing
If the valve timings are wrong then the valves open and close at the wrong times, thus preventing effective combustion and the car either uses a lot of fuel and produces a lot of exhaust, or won’t run at all.
4. Blocked exhaust
The exhaust removes the products of combustion from the engine. If the exhaust is blocked, then the pressure in the exhaust pipe is increased and the engine does not run because exhaust cannot escape.
5. Oil problems
If there is an oil leak and you run out of oil, the engine does not get lubrication and this causes the engine to cease due to excessive heat.
Although even a brand new engine can develop these faults, most working engines work with these faults not exceeding a tolerance limit. If it does exceed the tolerance limit, then the engine does not work effectively, or work at all.