The maintenance of a car encompasses many elements beyond the common change of oil and filters. Many other parts suffer wear over the life of the car and proper maintenance often prevents costly breakdowns to a very large extent.
In the following we will analyse the differences between the maintenance required for a car with a diesel engine and a car with a petrol engine.
The overhaul of the engine is the most common maintenance that is usually done on cars every certain period of kilometers. In both cases the oil and the different filters are changed, but the main differences are centred on the constant change of the Fuel Filter in the case of the Diesel, whereas in the Gasoline engines this filter is secondary.
In the Diesel it is very important its periodic substitution since the systems of direct injection to high pressure as well as the pumps of injection are elements of very high mechanical precision and of a very high cost of repair or substitution, reason why to assure with each change of filter of fuel that to the circuit of injection impurities will not arrive impurities that can damage the system, is vital to assure its longevity and correct operation.
Continuing with diesel engines, at each service check the glow plugs or glow plugs, which preheat the fuel to help the correct starting of the engine.
Petrol engines, on the other hand, require periodic checking of the thickness between the electrodes of the spark plugs, in order to ensure a correct spark gap and, therefore, a correct functioning of the engine. If the spark plugs do not look correct, the entire set must be replaced. It must also be checked for oil or carbon deposits.
As for the types of oil used, the most modern diesel engines are equipped with particulate filters, so the oil must be specific for this type of system and have the approval of the vehicle manufacturer.
On the other hand we have the engine belts, both the Accessories and Distribution. In the case of accessory belts, maintenance does not differ according to the type of motor. It is usually replaced together with the timing belt or in case of disassembly to perform an intervention. However, if it shows abnormal wear or cracks, it must also be replaced.
In the case of timing belts, the situation differs much more. Older diesel engines had to be replaced between 90,000 and 120,000 kms, while today, thanks to Common Rail technologies, their life is extended to over 200,000 kms and even changed every 240,000 kms.
In the case of petrol engines, their replacement is still recommended between 120,000 kms and 150,000 kms, depending on the manufacturer. In case the distribution was sent by metal chain there are no maintenance differences between different types of engine.
In the case of anti-pollution systems, the maintenance of a Diesel is much higher than that of a Gasoline. As previously explained, Diesel equipped with Particulate Filters in the long run end up blocking these filters, so that some manufacturers require a special additive that injected together with the fuel, “burn” these residues and thus clean the Antiparticulate Filters.
This additive liquid must be refilled at certain times, depending on whether the vehicle is used mainly in urban or mixed conditions.
Another aspect of Diesel maintenance is the cleaning of EGR (Exhaust Gases Recirculation) valves or exhaust gas recirculation.
This system derives part of the engine exhaust gases back to the intake to be re-burned and remove a small part of the solid particles, but consequently these valves eventually end up filling with charcoal, clogging and causing an erratic operation of the engine, so cleaning every 100,000 km (or less if operating in urban cycle) is highly recommended.
On the other hand, gasoline engines do not require special attention in anti-pollution systems, although due to the nature of the exhaust gases and their reaction with the condensation of the ambient humidity produced in the exhaust, it can corrode and break.
After seeing the differences in the engine, we’ll continue through the transmission. The clutches of cars with diesel engines tend to fatigue less and last longer, because the very high torque offered by these engines means that we have to change less gear, use less clutch and, above all, in the moments of starting from standstill is not necessary to revolutionize the engine so much to start moving the car.
For the opposite effects, the clutches of a gasoline engine usually last less kilometers. On the other hand, Diesel cars and their clutch systems have other maintenance. The so-called Bimasa engine flywheels usually break much earlier in a Diesel than in a gasoline, given that as we commented the bulky Torque of a Diesel makes work much more intensely this element of the transmission.
Brake system maintenance
Finally, the braking system also requires different maintenance depending on the type of engine the car uses. Since diesel engines weigh more, cars with these engines are usually a few kilos above those of petrol, so the braking force must be higher and therefore, the wear of discs and pads in the long run is higher in a diesel than in a petrol.