Engine problems are some of the most common auto problems that any car owner encounters regardless of the age, make, mileage or model of the car. This is perfectly understandable; after all, your car’s engine is the hardest working component and is literally the heart of your car. As the car accumulates more mileage or grows older, engine breakdowns tend to become more frequent. Car engines, however, sometimes break down even when they are frequently and properly maintained. In many cases, engine problems are caused by simple things like a loose gas cap or a dirty air filter, while in other cases the underlying problem is more complex and requires a professional mechanic shop to diagnose and fix.
Here are 3 of the most common engine problems and their causes.
1. Your Engine Fails to Start
A no-start condition is by far the most frequent engine problem encountered. If your car has a clicking noise but the engine fails to start, this is usually an indication that there is something wrong with the battery. If the engine cranks but fails to start, the problem could be ignition-related or fuel system-related.
The common causes why engines fail to start are:
- A low or discharged battery
- Loose or corroded battery cables
- Failure of the starter motor relay
- Ignition switch failure
- Clogged fuel filter
- Defective fuel pump
Engine overheating is another common engine problem. The most common reason for an overheating engine is low coolant level. A check on the coolant overflow reservoir will determine if the coolant is leaking. Most cars come equipped with temperature gauges or warning lights that alert the driver when the engine starts overheating. Frequent overheating can easily lead to serious damage to the engine and require expensive repairs. The cooling system should be properly maintained to ensure that it remains in top condition. A cracked engine head or a blown gasket can also cause the engine to overheat and lose coolant resulting in white exhaust smoke.
The most common reasons for engine overheating are:
- A faulty thermostat
- Dirty or low coolant level
- A kinked or broken radiator hose
- A non-functioning cooling fan
- A defective radiator cap
- Internal or external coolant leak
- Dirty air filter
3. Service Engine Soon Light
All modern cars come equipped with an ECM (Electronic Control Module) that controls engine operations and performs onboard diagnostics. When the system detects any problem with your engine, transmission, or powertrain controls, it triggers the ‘Service Engine Soon Light’ or ‘Check Engine’ in some cars, to alert you to a potentially serious fault that requires urgent repair. If you get blue exhaust smoke as well as the service engine soon light, this is usually an indication that your car has an engine oil leak. To determine the exact cause of the oil leak, an ASE-certified mechanic shop can retrieve your car’s trouble codes that are usually located within the onboard electronic control module.
The service engine soon light can be triggered by:
- Electronic control module failure
- Loose or missing gas caps
- Worn out or damaged spark plug and wires
- Defective distributor or coil packs
- Fuel quality problems
- Emission control faults such as the engine sensor
Common Sensor Problems
Your car comes equipped with several oxygen sensors and a mass airflow sensor. When these important sensors fail or malfunction, your car’s Check Engine Light or Service Engine Soon Light is triggered.
An oxygen sensor monitors unburned oxygen in the exhaust gases to determine how much fuel is burnt. Most cars come equipped with 2-4 oxygen sensors. Your mechanic shop will diagnose the code from the scanner to determine which of these sensors have failed. Oxygen sensors frequently fail when they get clogged with too much oil ash. Faulty sensors lead to reduced fuel efficiency and increased emissions. Failing to replace the faulty oxygen sensors often leads to severe damage to the catalytic convertor, which costs thousands of dollars to replace. That is why it’s very important to replace oxygen sensors as soon as they start malfunctioning. Replacing faulty oxygen sensors is many times cheaper than replacing a busted catalytic converter.
The mass airflow sensor balances the air/fuel mixture that is delivered to the engine. A faulty mass air flow sensor results in increased emissions, decreased fuel mileage, and in bad cases can cause your car to stall. A common cause of failure to the mass airflow sensor is an improperly installed air filter or a worn out air filter. If you notice your car stalling a lot, then you should have the MAF sensor checked. It usually costs a few hundred dollars to replace it.
Replacing a failed catalytic converter is one of the most costly repairs that are engine-related. The catalytic converter converts carbon monoxide and other harmful materials present in your car’s exhaust gases into relatively harmless compounds. The first signs of a failed catalytic converter is a drastic reduction in fuel mileage and a non-responsive car that fails to go any faster when you push the gas pedal. The good news, however, is that catalytic converters don’t fail frequently in regularly maintained cars.
Many of these problems can be avoided by following the manufacturer’s maintenance schedule. Routine services such as oil changes, fuel filter and oil filter replacement and normal tune-ups are necessary in order to keep your car in great shape. A simple thing like neglecting to change your car’s air filter frequently can have a cascade of undesirable effects and often lead to damage of more costly components that warrant huge repair bills.