Direct Injection Engines and Associated Problems
We are seeing a lot of fairly new vehicles with GDI (Gas Direct Injection) engines with driveability problems and wanted to pass some information about them along to our customers, so that when you bring your vehicle in for service, you have a base understanding.
Direct injection engines are great for increasing power and reducing emissions, however, carbon building up on the intake valves is wreaking havoc with some of them. The carbon deposits cause the air/fuel mixture to be distributed unevenly leading to driveability problems and misfire codes.
We have been seeing problems with carbon buildup in engines for a long time, but the problem is much more severe in direct injection engines because the fuel and associated detergents are not hitting the back side of the valves. Oily air and debris from the PCV system gets pulled into the intake and then into the combustion chamber where it should be burnt off. In a port injected engine the fuel was injected into the intake manifold, allowing fuel to rinse off the valves. Now, in a direct injection engine the gasoline is injected right into the cylinder instead of onto the back of the valves, so that debris just gets baked on instead of being rinsed away.
Carbon buildup problems are starting to show up on engines now with as few as 15,000 miles on them. Problems like low power, engine misfires and in extreme cases, engine failure. With more than 45% of vehicles produced in 2016 using GDI technology, this is not a problem that is going away. What can you do about this? Maintenance, maintenance, maintenance.
To start with you need to have the engine oil changed at least every 5,000 miles with synthetic oil (I know, the manufacturer recommendation is probably higher than that, do you think they set those recommendations to help you keep your vehicle in good running conditions for 300,000 miles? No they want you to buy a new car every four years or sooner) Second, you should have the induction system cleaned and often, starting at 15,000 miles. Finally it’s important to keep up on reflashes released for the PCM. On most vehicles we can hook up to your vehicle with a lap top and tell if you have the latest software updates and download them as needed. Manufacturers will make adjustments to engine timing through software updates that will help.
If you have questions about GDI engines, feel free to stop in or email us anytime at firstname.lastname@example.org. As always, thank you for your business!