According to the logic of things, as technology develops, engines should become more reliable, however, as experience shows, this does not happen. Moreover, it creates a lasting impression that the trend is in the opposite direction.
Of course, someone can say that this is nothing more than a grumbling of admirers of antiquity, but these people are right in this matter. There are a lot of reasons for the current situation in the engine world, and the effect of these reasons is summed up, resulting in various kinds of problems with engines. In this article, we will try to know why the modern era produces such weak motors.
1. The technical complication of a newer car engine
Perhaps the root of most problems is the increasingly stringent requirements for the environmental friendliness of engines and fuel consumption in the absence of new ideas and designs. We can say that all the innovations we observe are multi-valve designs, variable timing phases, direct injection, turbocharging, and compressors. All of the above appeared already in the 1950s and 1960s. As for the majority of technologies, they began to develop in the 1920s and 1930s.
A significant influence on the progress of piston engines in the first half of the twentieth century was exerted by the development of aviation, due to which, work on injection, multi-valve designs, and all types of boost were accelerated. In the automotive industry, these technologies were used only on the most advanced cars and racing engines. As for the widespread use of these technologies, it became possible only in the 90s, when cheap and reliable electronics appeared.
Around the same time, the legislation obliged car manufacturers to maintain certain rates of fuel consumption reduction, and the norms for the emission of harmful substances into the atmosphere began to gain more interest. At first, it was enough to introduce unconditionally advanced technologies for this. At this time, two-valve structures were quickly replaced by multi-valve cylinder heads. This happened mainly for the reason that the exhaust of such an engine was cleaner even without a catalyst.
It is natural that both the number of parts in the timing mechanism and the complexity of its maintenance immediately increased. Progress in metalwork has made it possible to complicate the engine.
An undoubted breakthrough was also such innovations as integrated engine management systems, thanks to which it became possible to bring together the ignition control, transmission, injection, service procedures, and the transition to electronic fuel injection. Due to this, both the characteristics of the engines and their reliability have increased.
True, many experienced car enthusiasts will be able to recall the distrust that met the first injection cars and the skepticism of garage workers who warned how difficult it is to repair such systems (unlike a simple carburetor, for example). However, in the end, history gave everything a well-deserved assessment: injection systems turned out to be more reliable than old power systems, despite the minus that it was much more difficult to repair complex equipment.
The next technology, which was massively implemented, was the timing system: i-VTEK on Honda, VVT-i on Toyota, VANOS on BMW, etc. To put it simply, this system allowed shifting the opening and closing times of the intake and exhaust valves, depending on what the engine speed is, to provide good traction, both at low and high speeds. Simply put, thanks to this, without impairing the efficiency of the engine, their power characteristics have improved.
This design, although it was not very difficult to implement, was too new, and for some manufacturers also quite problematic. For example, wearing parts have appeared and, as a result, owners of such cars have new problems, for example, breakdowns and system failures.
Then came the time for the massive introduction of turbocharging. Thanks to it, in the Japanese and European driving cycles of measuring fuel consumption, it became possible to use a kind of loophole. Fuel consumption has decreased and, at the same time, the dynamic parameters of cars have greatly improved. Of course, a turbocharged car is much more difficult to operate than cars with naturally aspirated engines, and even minor violations in the operation of all systems pose a certain threat to such cars.
The latest technology, which began to be massively introduced (albeit gradually), was direct fuel injection. On the one hand, it makes it possible to significantly increase the capabilities of the engine, but at the same time, it requires the use of complex components that have a limited resource and are very vulnerable due to harsh working conditions and accurate design. And, in addition to the fact that the probability of failure increases significantly, the cost of repairs also increases.
However, the use of these rather old technologies, in general, was not a problem, since they were largely worked out long before they began to be massively introduced on racing engines. And although during the transition to mass production, miscalculations and errors occurred, in general it can be said that these technologies are certainly progressive. It’s just that their implementation was too fast and too massive, which was necessary to fit into the framework provided by law. And only the growth rate of efficiency of new engines could not keep up with the tightening of requirements.
2. Reducing friction losses
In the process of engine evolution, pretty soon there were signs of complications, like dull intake systems, as well as clumsy attempts to reduce internal friction, which, was achieved because the nodes became less reliable. On the one hand, the less friction – the higher the efficiency, but due to what? First of all, it should be noted that many plain bearings in the engine were simply reduced in size. The sizes of chain links, camshafts, sizes of crankshafts, and piston fingers were also reduced.
Of course, this was accompanied by the fact that metallurgists created new alloys, so new parts were more durable. That’s just not everywhere and not in everything. For example, engines have become much worse at enduring overloads.
In order to further reduce friction losses in bearings, as well as energy costs for lubrication, it was necessary to resort to more and more liquid oils, and to reduce their pressure in the system
But such “oil” innovations did what was to be expected: the thinner the oil, the less stress-resistant the material. In addition, a controllable oil pump is not only more complicated, but also does not provide a pressure margin for the most common engine operating modes.
3. Increasing Operating Temperature
It should be mentioned that to increase the efficiency and environmental friendliness of the engine at low load, an attempt was made to increase the operating temperature of the engine. And to avoid power losses, controlled thermostats were introduced, which allowed the engine to cool slightly under load. True, the increase in temperature had an extremely negative effect on the aging of rubber and plastic engine parts, the rate of oil wear, etc. In a word, the trouble for motorists has increased.
Also, controlled thermostats are not able to instantly lower the temperature of the engine, and often the temperature of the motor under load is above the optimum, which leads to detonation and accelerated wear. And although oil began to be changed less frequently, no breakthroughs in the technologies for its production also occurred.
4. Piston System Relief
All other reasons for reducing the reliability of the engine, which will be described below, are related to the main factor, although they could have developed without taking it into account. Because that control over the combustion of fuel was transferred to the electronics with feedback, it became possible to significantly facilitate the piston group and many other parts of the engine.
Going back in time, how much horsepower a 1984 VW Golf could produce at 1.8 liters? With a carburetor – 90, with an injection on the GTI – 105-115. By today’s standards, very modest parameters. For comparison, the engines of the 1.8 EA 888 series currently have a capacity of 182 hp and an increase in torque. Thanks to the introduction of new technologies, it has become possible to create engines with such a degree of forcing that exceeds the parameters of ICE racing cars thirty years ago. And, of course, any increase in temperatures and loads automatically leads to faster aging of metals and a decrease in the resource as a whole.
5. Lack of time for a full engine test
Because of the sharp acceleration in the growth of requirements, car manufacturers, especially those who are among the leaders of the premium segment, had to abandon the practice of phasing the introduction of new technologies into old engines and, accordingly, from the gradual improvement of the design. Now it often happens that during the short life of a particular model in production, the series of engines change twice. Naturally, the testing time is also reduced, as is the number of tests conducted with the new engines.
Most of the tests are now performed on computers, but since the software often has errors, as a result, constructions that obviously have not been finalized go into production and their problems are already fixed, as they say, “in the process”. Thus, five or six routine replacement of liner materials and types of nozzles, piston groups and piston rings is the price for the “progressiveness” of the engine.
6. Diagnostic difficulty and rare maintenance
If you look under the hood of a modern car, and then under the hood of an older one that came out in the 90s, you will see how more compact the engines have become and how much more tightly they now fit into the engine compartment. No one wants to carry air, and the requirements for increasing the internal space while maintaining the compact size of the car over time have only increased.
Sometimes this is accompanied by a clear deterioration in the operation. However, in any case, this leads to a complication of the diagnosis and large periods that it takes. Workshops now have to rely more on electronic self-diagnosis systems, and less on connecting additional monitoring devices and visual control. Also, service procedures are now less frequent, therefore, the ability to identify a problem at an early stage is also significantly reduced.
7. Working conditions
The last factor, perhaps, was an increase in the average engine load. Since the new automatic transmissions are designed to reduce fuel consumption, on the other hand, they force the engine to work in such ways that create maximum loads at certain speeds. On the one hand, this saves fuel, and on the other, it does not pass without a trace for the units. New automatic transmissions make it possible to easily and without hesitation use the full power of the engine, and by reducing the noise of the units, the process becomes easy and enjoyable. Well, you have to pay for it, as always, with the reliability of the engine.
Each of the above reasons alone creates a steady feeling that many new cars have constant engine problems. Moreover, most progressive manufacturers have the most problems, while the more conservative ones have fewer problems. In fact, in general, the number of failures in the warranty period becomes lower, which is a consequence of the work of quality control systems.
Also, it became possible to timely correct errors in problematic series of engines or to completely remove them from production, if it is impossible to correct the situation by small forces. Everything that goes beyond the warranty period is already outside the interests of the manufacturer. It is possible that after the warranty period, the car travels very briefly, and its repair will be expensive and require the use of special tools.
Until then, the owner of the car will be able to fully enjoy it – in the end, it is both more economical and faster. Moreover, the cost of fuel saved may be even higher than the increased expenses for the upcoming engine repair, which the driver will sooner or later face.