I would like to point out at the beginning that this is true not only for Hyundai and KIA GDI engines, but for all engines of this type!
GDI engines (gasoline direct injection) and TGDI engines (Turbocharged Gasoline Direct Injection) are a type of gasoline engine that uses direct fuel injection. This means that the fuel is injected directly into the cylinder and not through the intake valves. GDI engines have many advantages over traditional MPI and central ‘carburetted’ engines, such as better fuel efficiency, lower emissions and better performance. What has an advantage also has a disadvantage. Since this is also a technical item, and as the operating time progresses, maintenance must be carried out, along with major maintenance, which the operator must perform at intervals. The same applies to engines with GDI/TGDI operation.
In addition to periodic maintenance, preventive maintenance must also be carried out during mileage and/or time intervals.
Piston cap burnout can be caused by a number of factors, including:
- Poor quality fuel GDI/TGDI engines are sensitive to poor quality fuel which can damage the high pressure injection system. Poor quality fuel can be contaminated and contain ingredients that can increase the risk of piston crown burnout.
- Low compression can lead to piston crown burnout as it does not generate enough heat for the fuel to burn completely. Low compression can be caused by several factors, including worn parts, poor quality oil, and improper maintenance.
- An incorrect air to fuel ratio, i.e. the mixture, can contribute to piston crown burnout by getting too much or too little fuel into the cylinder. The air-fuel ratio is adjusted by the engine control unit, but many factors can interfere with the adjustment, including poor quality fuel, worn parts, and improper maintenance.
- Faulty or dirty GDI injector, GDI/TGDI injectors need to spray fuel into the cylinders very precisely for the engine to run properly. If the spray pattern is incorrect, the fuel will not burn (distribute) properly, which will cause overheating and burnout of the piston.
- Bad combustion timing, a cause-and-effect answer is possible here, the injected unit of operational fuel does not burn properly in the cylinder, it may remain in the cylinder, or burn in the exhaust downpipe at the catalyst. Therefore, it is important to visually check the engine control, as it adjusts the valves and the depth of their opening to the working stroke. The proper operation of the control can be disturbed and affected by many factors, including worn parts, poor quality and quantity of engine oil, and improper maintenance.
- The engine’s cooling capacity decreases, which is neglected by the owners in most cases. If the heat dissipation of the engine cooling system is not sufficient, this can also lead to burnout of the piston cap. The engine overheats unnoticed, the combustion temperature in the cylinder at the cylinder wall and cylinder head increases, and the unburned or intact injected fuel burns in an improperly programmed form, thus causing self-ignition. The cooling system should be checked regularly and the fluid replaced if necessary.
- Failure to replace the spark plug, GDI/TGDI engines have special spark plugs, they play a particularly important role in creating proper combustion. If the spark plug is very worn, has soot, or its electrode is burnt and the spark gap increases, it cannot ignite the mixture, it cannot form a spark of sufficient power so that the fuel mixture burns properly. It is generally recommended to change spark plugs after 90,000-105,000 kilometers.
What can be done to prevent or minimize piston burnout?
- The cleanliness, fluid level and condition of the engine cooler must be checked regularly
- Engine oil, spark plugs and fuels of the correct quality must be used
- The engine’s fuel system must be cleaned regularly, also due to the high ethanol content
- You need to maintain your car regularly, this does not only mean changing the oil
- The suction valves must be cleaned regularly, because fuel does not reach the GDI engine during operation
- It is necessary to check injection valves and their atomization pattern every 80,000 – 105,000 kilometers
- It is necessary to change the fuel filter at appropriate intervals, in conjunction with a fuel pressure check
Burnout of the piston cap can occur due to a number of factors:
- Inadequate fuel quality
- Low compression, fuel mixture error
- Bad injector, bad spray pattern
- Air channel restriction at the valve
- Inadequate control
- Worn out spark plug
Summarizing the above, I think it is important to draw attention to the fact that, according to experience and the literature available on the Internet, GDI (gasoline direct injection) and TGDI (Turbocharged Gasoline Direct Injection) engines are characterized by deposition, coking and thus the cross-section of the intake duct and valves. decrease. All of these can cause engine failure, which can cause a lot of headaches and eat up costs. If we know that the normal operation of the engine supports such additional high maintenance, so that it can be used safely in the future, it must be done. You have to prevent the development of bad combustion, that’s for sure. Information spreads among users by word of mouth, surely there is a cheaper solution, possibly an additive. Unfortunately, there is no liquid engine doctor that can solve this, since we are talking about a GDi (Direct Multipoint Injection) engine. For this issue, we recommend cleaning the nut intake valve, intake channel and piston cap. As part of the cleaning process, after disassembling the parts, the GDI injectors are also inspected, cleaned or replaced as necessary. In any case, it is advisable to schedule together with large services. Also, after buying a car where the complete history is not known and we do not know whether the cleaning and high-pressure injection have been checked. With appropriate expertise and type-specific knowledge, an experienced eye can confirm the need for high maintenance at the moment of purchase.
In addition to these, it is recommended that you use an additive in the engine oil, which helps prevent piston cap burnout, even in the case of existing oil consumption. The engine oil must be changed periodically so that the old engine oil drains properly from the engine. These additives usually contain ingredients that reduce friction and protect engine components from abnormal wear. This may be silly, but it can be said that we also take vitamin C or D in order to be less sick.
Cleaning is important, at least for these reasons:
- Improves engine performance, cleaning removes dirt from the intake valve, ducts, which improves air-charge volume, soot is removed from the injectors and cleaned as needed, which further improves combustion and thus improves engine performance and flexibility
- Fuel consumption normalizes after the cleaning process, combustion improves and specific fuel consumption decreases, the engine runs smoother
- Reduces harmful emissions, cleaning improves combustion and reduces harmful emissions, catalyst efficiency may improve depending on the degree of wear
- It increases the lifetime of the engine, the cleaning removes dirt from the intake valve, channels, piston crown, and the jet pattern of the injectors also improves. Due to the totality of these, the combustion in the cylinder improves, which reduces abnormal further wear in the engine during operation.
- Don’t worry, we know the specifics of the engine, so if we have the cleaning done, we will prevent and minimize further increased coking and thus give the opportunity for normal operation. You only have to pay attention to the additional fueling and proper servicing.
- Increase in value, the principle of a careful owner, this is an investment in the future, it makes your car stand out when selling, as it has a careful and forward-looking owner
It is important to note that these direct injection GDI and TGDI engines work without problems for years, every brand makes these engines and uses them in the middle and high end because of their efficiency. However, if you’re buying a car with a direct injection engine, it’s important to be aware of the potential problems and maintain your car regularly to prevent major and costly additional problems from developing.
If you experience any problems, contact a qualified type-specific mechanic.
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