If you read my last article, you’ll know that we’ve established the fact that the GDI engine is the greatest thing since cupcakes as far as the automotive industry is concerned. But then again, every time the industry comes up with new technology it is always the best of the best no matter how bad it might be. I won’t bore you with all the failed ideas that not only did not work but cost you, the consumer untold dollars to repair and maintain these ideas.
The biggest issue that I see with these GDI engines I that they just showed up and there was no training or instructions to the techs or the public on how to keep these engines running perfectly. It seems that the American consumer has been held for the research and development of all these new ideas.
Here is the crux of the issues; because of the dependency of multiple systems of the engine, a complete and comprehensive maintenance plan is necessary. First and foremost, these engines have multiple fuel pumps, one in the fuel tank (a lower pressure delivery pump) that feeds a higher-pressure pump on the engine (it pumps at super-high pressures that atomizes the fuel so it can run leaner). This means that the type of fuel that you run and how you maintain the filters is the first form of preventive maintenance. As I have always insisted using a Tier 1 or Top tier fuel is imperative. These fuels are clearly marked on the pump with a decal or you can Google top tier fuels and get a list of all those fuel companies that comply. An easy way to understand this is that most “BRANDED” nationally known fuel suppliers are typically Tier 1 fuels. Keeping your fuel filters replaced at least once every 30,000 miles or every 2 years is imperative for good fuel pump health. The easiest way to promote good fuel pump health is to never run your tank past a quarter of a tank. The fuel pump is submerged in the tank and in the fuel because they are using the fuel as a lubricant and a cooling medium. When you run your tank way down the fuel pump is hanging in the air and has the opportunity to overheat, thus lessening its life dramatically.
The second and probably MOST important is to change your oil and filter frequently and by the factory stated interval, if not earlier. Using a good quality synthetic oil or a properly rated oil filter is imperative with these engines. Oil filters are rated; a normal off-the-shelf filter is usually rated for 3000 miles, a GOLD filter is rated for up to 7500 miles, and a Platinum filter is rated for 12000 miles. The difference in these filters is not only the amount and type of filtering media but also the valving within the filter. If you use a less expensive filter and overrun your oil change interval, then the media clogs and the valving allows the oil to pass through the engine unfiltered. This abuse of the oil will affect the high-pressure fuel pump that actually runs off of the camshaft and the variable timing components. All these components are expensive.
The biggest problem with the GDI motor is that the fuel is injected directly onto the piston face and by-passes the valve faces. Initially, the fuel washed the valve faces of any carbon deposits and kept them somewhat clean. Spraying below them allows carbon deposits and oil bypass deposits to accumulate on the valve faces. Due to the increase in combustion chamber temperatures, these deposits harden quickly and end up affecting the sealing of the combustion chamber causing misfires. Ignored long enough these deposits will break off and lodge themselves between the cylinder wall and the piston rings and scoring the walls causing blow-by.
Education is so important and the manufacturers in an effort to show maintenance costs as low as possible are only short-changing you the consumer.