Vehicle Systems That Require Regular Inspection & Maintenance

Passenger cars, single- and double cab bakkies, SUV’s and Minibus taxis are all vehicles that have various systems that require regular inspection and maintenance. This is applicable to diesel, petrol and electrical models. The following is a general summary of the various vehicle systems that need regular inspection and service and /or replacement. A description of general symptoms that indicate possible problems is also included to assist vehicle owners & drivers to help avoid untimely brake down and unnecessary extra cost. Contact an Auto Repair Professional, as listed in the Auto Repair Directory to assist nationwide across all regions of Southern Africa.

Charging and Starting system - including the Battery

A vehicle’s charging and starting system (including a battery), ensure dependable vehicle operation, day and night under all types of driving conditions. It is important to check these systems regularly.

The battery stores electrical energy and the starter converts that energy that turns the engine to start. The alternator produces electric current to replace what the starter used during start-up and to support electrical loads when the engine is running. An ignition module, including the ignition coil produces the high voltage for the ignition system. This creates a spark at the spark plugs and ignites the air/fuel mixture in the engine. A belt transmits power from the vehicle’s engine to an alternator’s pulley, along with other accessories. Frequent switching an engine on/off will cause more wear on the charging and starter system than a single longer distance trip. Weather and driving conditions also impact the longevity of a battery in conjunction with the vehicle’s age, kilometres done and the extensive use of in-vehicle infotainment and communication systems. Symptoms indicating possible problems with the Charging & Starting system includes:

• System warning lights illuminates - e.g. “Check Engine” or “Battery
• Headlights and interior lights dim
• Infotainment and other electronic accessories fail to operate

Braking System

A properly operating brake system control the safe operation of a vehicle under all driving conditions. As it is a critical safety system, it should be checked immediately if any problems are experienced or suspected! When the brake pedal is engaged, hydraulic pressure is generated in the master cylinder. This pressure engages through the hydraulic lines and hoses to the wheel cylinders and callipers that force the brake pads against the brake drums, and in turn against the rotors. The friction that results from this process, slows the vehicle. The vehicle’s speed reduction is relative to the amount of force applied by the driver to the brake pedal. Brakes are a normal wear item will need replacement from time to time. The hand brake should also be inspected and adjusted at service intervals. The replacement intervals are determined by driver habits, the quality of brake system parts and road conditions. Symptoms indicating possible problems with the Braking system includes:

• Dashboard warning lights illuminates
• Coolant fluid leaks
• Engine overheating
• Air conditioning systems not working properly
• Abnormal noise during the start-up or operation of the vehicle, specifically when applying the brakes
• The smell of burning rubber

Fuel System

A vehicle’s fuel system is designed to operate with the rest of the engine control system in delivering optimal performance. The fuel system transfers fuel from the fuel tank via the fuel line through a fuel filter to the injectors. A constant fuel pressure is ensured by a pressure regulator to guarantee a constant fuel supply-, and therefore engine performance under a variety of speed and load conditions. Fuel injectors deliver a measured amount of fuel into the engine combustion chamber. Most vehicles use a return line system to return unused fuel back to the fuel system. Intervals for fuel system maintenance are influenced by many factors that include Fuel quality, Vehicle age, Operating conditions and the Vehicle’s maintenance history. Symptoms indicating possible problems with the Fuel system includes:

• “Check Engine” light is illuminated
• Fuel smell in passenger compartment
• Poor fuel economy
• Engine will not start or stop during operation

Emission & Exhaust System

The emission system keeps the engine running cleanly and efficiently under all operating conditions. It controls and reduces the emissions, harmful exhaust gases and fuel vapour escaping from the fuel tank. This is done through several sensors, computerized engine controls and the exhaust components. Factors including the effectiveness of the emission system includes driving conditions, vehicle age, type of spark plug electrode material, quality of vehicle maintenance, fuel quality, state of the vacuum hoses and damaged or worn sensors. Symptoms indicating possible problems with the Emission system includes:

• Excessive smoke and vapours
• Noise from the exhaust system
• A flashing warning light on dashboard

Engine Cooling System

The engine cooling system serves important functions. It removes excess heat from the engine, it maintains an efficient engine operating temperature and brings the engine to the right operating temperature as quickly as possible. The water pump circulates coolant through the engine. The coolant absorbs heat and returns it to the radiator where heat is dissipated. The thermostat regulates the coolant temperature to keep it consistent for efficient engine operation. The engine cooling system affects the vehicle’s dependability and engine longevity. Various factors influence the efficiency of the system such as maintenance and replacement cycles, driving habits, operating conditions, type of coolant used and the type of- and age of the vehicle. Symptoms indicating possible problems with the Engine Cooling system includes:

• Warning light illuminating on the dashboard
• Overheating
• Fluid leaks = need to refill repeatedly
• A sweet smell emanating from the engine compartment

Steering and Suspension System

The steering system is a key safety-related system that is designed to enable the driver to control and continuously adjust the steered path of the vehicle. The suspension maintains the relationship between the wheels and the vehicle’s frame. It interacts with the steering system to provide vehicle control. Over time, steering and suspension components wear out and require replacement. Regular checks are critical to maintain safety. Factors that affect wear include driving habits, the type of system, frequency of chassis lubrication and wheel alignment. Symptoms indicating possible problems with the Steering and Suspension system includes:

• Vehicle draw to one side- especially when applying the brakes
• Uneven tyre wear
• Excessive vibration or noise
• Loss of steering control

Belts and Hoses

Belts and hoses are essential to the engine cooling, air conditioning and charging systems. The timing belt keeps the crankshaft and camshaft mechanically synchronized to maintain engine timing. Transmission belts (v-belts, serpentine belts, fan belts, alternator belts) transfer power from the front of the engine to accessories such as the air conditioning, the charging system and fans. Radiator and heater hoses carry coolant to and from the engine, radiator and heater core. Typical wear that affects the replacement cycle includes the vehicle age, corrosion, oil contamination, belt tension and broken hose clamps. Symptoms indicating possible problems with the belts or hoses includes:

• Squeaky noise during start-up or engine operation
• Dashboard warning light illuminating
• Coolant leaks
• Air Conditioning failure
• Engine overheating
• A smell of burnt rubber

Filters & Fluids

The oil filter traps contaminants, allowing the engine oil to flow through the engine unrestricted. The fuel filter separates harmful contaminants that may cause problems with carburettors or fuel injectors. The purpose of the engine air filter is to prevent dust, dirt and other environmental contaminants from getting into the engine, turbo and airflow sensor in fuel-injected cars. Cabin air filters clean the air passing through the vehicles ventilation- and/or air-condition system, stopping contaminants including pollen, bacteria, dust and fumes from entering the vehicle’s passenger compartment. Filters and fluids are normal wear items that require regular checks and replacement. Factors that affect replacement intervals include mileage, driving habits, road and driving conditions and the type of filters used. Symptoms indicating possible problems with the filters and fluid includes:

• Poor fuel consumption
• Hesitation in acceleration
• Fluid leaks – excessive refilling
• Odour in passenger cabin

Transmission System

A transmission is another name for a vehicle’s gearbox and the clutch, clutch disk and other components transferring power from the engine to the wheels. It keeps the engine’s output optimally matched to the speed and load conditions. The torque converter, connected to the automatic transmission/transaxle input shaft, connects, multiplies and interrupts the flow of engine torque into the transmission. Universal and/or Constant Velocity (CV) joints connect to the driveshaft to transmit output power from the transmission to the rear axle and /or the front axle. These joints also allow the driveshaft and/or CV shaft to work at an angle. The several different types of transmission fluid serve multiple purposes that cleans, cools, lubricates, transmits force, transmits pressure, inhibits varnish build-up and continually protects the transmission. Wear and tear on the transmission can be influenced by driving habits, towing, operating conditions and service intervals. Symptoms indicating possible problems with the Transmission system includes:

• Warning light illuminating on dashboard
• Grinding gears
• Difficulty in changing gears
• Gears slipping – specific in automatic transmissions
• Fluid leaks or low fluid levels

Lights, Wipers and Windscreens

Lights, park control systems, windscreens and windscreen wipers play a critical role in safe driving and should be repaired or replaced at once when faulty! The windscreen wiper system keeps excessive fluids and dirt from building up on the windscreen and removes them to maintain clear visibility. Lights and wipers are normal wear items that require periodic replacement. Factors affecting replacement interval include age of the vehicle, operating conditions, frequency of use, material and type of lights and wipers. Symptoms indicating possible problems with the Lights and/or Wiper systems includes:

• Warning light illuminating on dashboard - lights
• Rapid signal light blinking
• Poor visibility when switching lights on at night
• Alerts from other drivers - usually flashing their lights

Tyres, Rims & Shocks

A tyre can lose up to half of its air pressure and not appear to be flat, check regularly! A good habit is to check tyre pressure every time you visit a fuel station. The chief reason for tyre replacement is friction from moving contact with road surfaces, causing the tread on the outer perimeter of tyres to eventually wear away. Increased tread wear on only one side of a tyre is often a sign of poor wheel alignment. Under-inflation can lead to tyre blowouts. A bad jolt from hitting a curb or pothole can disrupt wheel alignment and damage your wheel rims. Wheel balancing is important because wheels lose their balance over time. Factors concerning the weight distribution of your vehicle, road conditions and tread wear can cause an unevenness in the tyres, which can then lead to further uneven tread wear. As a result, the vehicle might shake or vibrate while in use. Nitrogen as a tyre fill option should be considered as the key benefits are a slower rate of pressure loss and cooler running temperature of tyres, that result in up to 20% extended tyre tread life! Shocks, or shock absorbers are responsible for two functions. Firstly, they are designed to absorb any vibrations, jolts or bounces experienced while driving. Secondly, they always assist in keeping all the tyres in contact with the road. This aids in maintaining good braking and handling ability. There are three common types of shocks - Telescopic shock absorbers, Strut type shock absorbers and Spring seat shocks. Shock absorbers life expectancy, as well as the struts, is at least 4 to 5 years. Most auto manufacturers recommend that replacement of shock absorbers at least every 80,000 kilometres. Vehicle owners should also consider Symptoms indicating possible problems include:

• Vibrations while driving
• Swerving, sliding or nosediving while braking
• Instability at highway speeds
• Uneven tyre wear
• Leaking fluid
• A knocking sound that emanates from the front or rear wheels