1. Electronic diagnostics and maintenance are less frequent in order to save money.
The increase in the interval between maintenance has led to the fact that a car uses the same consumables much longer. Consequently, the "life" of the engine becоmes progressively infrequent.
2. Invalid engine testing.
Modern engines are tested with computers with the help of special programs, but not under the real-life conditions. People have started to trust the indications of electronic diagnostic devices more than specialists.
3. Increase in working temperature.
To place a powerful unit in the engine compartment of the car, it is compressed to a minimum. And to get high rates of environmental friendliness and economical efficiency, engineers have decided to increase the working temperature of an engine. At close quarters, all engine parts are under the deleterious influence of overheating. Plastic and rubber parts wear out quickly. Even metal parts, made of high-quality alloys, are vulnerable to. Due to the increase in working temperature, the quality of the oil goes down rapidly. In modern engines, a conventional heat regulator has been replaced by a controllable one. The controllable heat regulator cannot immediately reduce the temperature of the oil.
4. Technical complication of an engine.
In pursuit of efficiency and good environmental performance, engineers have implemented such measures which led to increasing the valves per cylinder, the introduction of direct injection and turbocharger system. And more specifically:
- with the advent of the multivalve cylinder head, the gas distribution mechanism has become much more complicated, and the process of its maintenance has become more complicated too.
- electronic fuel injection has significantly increased the economical operation.
- introduction of variable cam timing system has allowed shifting the time of opening and closing of inlet and deflation valves, depending on engine rev.
- turbocharger system has allowed to significantly increase the engine performance with a small fuel consumption.
As a result of the technical over-engineering of an engine, the maintenance has also become more complicated. The new systems have become "more delicate" than the old ones and are more prone to breakdowns, and consequently, require more careful treatment. The diagnostics of trucks and passenger cars are required more often.
5. Reduction in frictional loss.
To increase efficiency, the engineers went in for reduction of internal friction using less viscous engine oils. However, together with the viscosity reduction, they have received oils which are less resistant to loads and overheating.
6. Engine operating at ten tenths.
Again, in the struggle for economical operation, new automatic gearboxes have been implemented, and they allow to use the full potential of the engine. They force the engine to work at maximum load at a given speed. The process has become softer and noiseless, but less reliable.