GDI engine issues can be tough for car owners
One of the relatively new innovations in automotive internal combustion engines is the GDI or Gasoline Direct Injection. Every manufacturer from GM to Mercedes is using GDI in some way, shape or form in its ICE lineup. So new owners of a direct-injection engine that are not familiar with the issues related to GDI need to know some of the common problems to watch for. Owners of GDI engines also have to follow a different maintenance routine than a port fuel injection engine. In this post, I’m going to explain the meaning of GDI, some of the common GDI engine issues to look for and ways to prevent fuel system problems in your engine.
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Since many car owners don’t practice proper and timely maintenance on their vehicles, it’s no surprise that GDI engine issues are so common. Many car owners ignore the fuel system when it comes to maintenance and GDI engines are not maintenance-free fuel systems. It takes a steady maintenance schedule and a small monetary investment to keep a GDI engine running properly.
GDI means new engine problems to diagnose and prevent.
According to Wikipedia, the first mass produced vehicle with a GDI engine was the 1996 Mitsubishi Galant in the Japanese market. It was several years before GDI engines became mainstream technology. Now in 2023, it’s very likely that the engine under your hood is direct injected. That’s assuming you haven’t made the switch to an all-electric vehicle. Even Hybrid electric vehicles are using direct-injected engines under the hood. But what does this mean for owners of direct-injection engines? What should you know before buying a GDI powered vehicle?
Its also very likely that you are not practicing proper maintenance on your GDI engine. BG 44K engine treatment service is the leading fuel system additive for direct-injected engines. It runs around seventy dollars for three cans on Amazon, but it can save you thousands in potential repairs down the road by eliminating carbon that’s already developed or preventing carbon if you have been fortunate enough to keep your GDI engine free from it.
Diagnosing problems with a direct-injection engine can be different than a traditional internal combustion engine. This is because there are added components like the high-pressure fuel pump involved and carbon buildup can be hard to diagnose. It takes a technician with some experience that knows how GDI engines work to figure out problems related to the fuel system. The best way to fix problems with a direct-injected engine are to prevent them, period.
Check this out: Autel’s PS100 vs Power Probe vs Snap On multi-probe
Why did GDI engines become popular?
With GDI engines requiring a little extra maintenance, it’s a fair question to ask why they became so popular in the first place?
The rise in popularity of the gasoline direct injection engine came at the same time emission standards mandated by the governments around the world for automakers started to stiffen up.
It’s a verified fact that GDI engines are more fuel efficient. Therefore they release less CO2 emissions than indirect or “port fuel injection” systems. Consider this. In the model year 2008, GDI engines held only a market share of 2.3% according to Green Car Congress. Ten years later, that market share had jumped to a staggering 51%. The EPA expects that number to be 93% by 2025, with almost all new plug-in hybrid ICE engines being direct-injected versus port fuel injected.
President Obama made changes to the CAFE standards.
It’s no coincidence that these numbers overlap with President Obama’s reign of the White House. As part of an effort to reduce fuel consumption and CO2 emissions, the Obama administration made updates to a set of standards knows as “CAFE” or Corporate Average Fuel Economy.
In the changes made to the CAFE standards by President Obama, the requirement was that by 2026, the fleet average fuel economy had to be 49% industry wide for passenger cars and light duty trucks. A whopping 8% increase in fuel economy by 2026 put a lot of pressure on auto manufacturers to start developing engines that were more fuel efficient and could run on lower viscosity oil. This is when the GDI engine started to take off in the United States and with cooperation from most other governments, the rest of the world followed suit.
Direct-injection engines are efficient, but are they reliable?
GDI engines are able to achieve better fuel economy by delivering fuel straight into the cylinder. This is in contrast to spraying fuel through the intake manifold over top of the valves in port fuel injection systems. But is reliability sacrificed for a few extra miles per gallon of fuel economy?
The process of spraying fuel directly into the cylinder is the cause of the most common GDI engine problem. Carbon buildup on the back of the intake valves causes major headaches for GDI engine owners. Using a can of BG 44K Fuel System Cleaner will work wonders. It tells you on the back of the can how to use the BG Fuel System Cleaner, so there is no excuse not to use it.
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Carbon build up on the intake valves cause misfires
In a traditional “port” fuel injection system, fuel is sprayed by the injector through the intake and over the intake valve. The fuel spray on the valve serves to cool and also clean the backside of the valve.
The way a GDI engine works is bypassing the intake and valve all together delivering raw fuel straight into the combustion chamber. Good strategy for emissions and fuel economy. Poor strategy for those poor intake valves now being bombarded with carbon deposits and no effective way of preventing it.
Read my post on the GM Ecotec line of engines and their poor design here!
The problem with the GDI engine depositing carbon on the intake valves is at some point, the dirty valve is going to fail to seat properly.
The dirty intake valves then cause a misfire that can leave folks who are uninformed on GDI engines baffled and chasing their tail replacing parts that don’t need to be replaced. Engine codes starting with P0300 will soon follow the misfire and will need to be fixed in order to inspect the direct-injected engine.
Can carbon be prevented in GDI engines?
Figuring out how to prevent carbon buildup in a GDI engine is not easy, but it’s not impossible. Here are a few ways I’ve learned in the past to help control the carbon build up in these direct injected engines. Following these maintenance tips can help to prevent those P0301, P0302 and up codes in a GDI engine.
- Use Quality Fuel.
Using premium fuel is one of the most important and effective ways to stop carbon from building up inside your cars GDI engine. The reason for this is because premium fuel contains higher quality detergents that will help to stop carbon build up in the engine and on the intake valves.
If you can’t imagine paying even more for gas, check out the free Upside app that gives you a .25 cent per gallon bonus on your first fill up and then gives weekly promotions for cents off per gallon at local gas stations. It costs me nothing and it definitely helps offset the cost, especially if you put a lot of miles in. Since inflation hit and grocery prices rose, Upside has even started doing grocery promotions and deals at the store, so that’s just another reason to download and sign up.
- Run a Fuel System Additive
Running a fuel system additive in your GDI engine is a no-brainer. Intake valves are not the only thing carbon has an effect on. Clogged injectors are a very frequent problem on GDI engines. Using a fuel system cleaner designed specially for direct injection engines will help to prevent carbon from plugging the injectors.
- Clean the valves DIY style on your GDI engine.
There is a widely used technique for cleaning carbon off valves called walnut blasting. VAG (Volkswagen Audi Group) seems to be the most prominent user of the technique similar to sandblasting. The problem with walnut blasting is is it’s not easy on the wallet.
That’s why I’m going to tell you about a method I’ve had success with in cleaning the valves on several GDI engines. Including a Mazda Skyactiv with the worst buildup I’ve ever seen.
I’ve tried two different products for this technique and both seemed to be equally effective. One was CRC GDI intake valve cleaner and the other was Lucas GDI deep clean. Both products serve the same purpose and are used in similar manners to clean the intake valves that have been subjected to carbon deposits for possibly hundreds of thousands of miles. Simply follow the instructions on the can. If needed, you can repeat the process.
- Change the oil in your GDI religiously
Another symptom of the carbon buildup in GDI engines is an increase in oil consumption. The same carbon damaging the intake valves will also cause the piston rings to stick, therefore causing the GDI engine to burn more oil than normal. One way to help prevent this is by changing the oil regularly and using oil made for GDI engines. The special oil for a direct injected car reduces the amount of vapor inside the engine that leads to carbon developing.
- Replace the spark plugs at regular intervals
The reason it’s important to replace the spark plugs regularly on a direct-injected engine is to prevent raw fuel from being left behind in the combustion chamber. If the spark plugs in your GDI engine are weak, carbon build up on the intake valves and throughout the engine will become a problem.
In order to prevent carbon buildup, there are spark plugs designed specifically for direct-injected engines. I would highly recommend that in the interest of maintenance, any vehicle owner with a GDI engine run these performance spark plugs.
NGK Laser Iridium IX Spark Plugs are highly recommended for GDI Engines
One of the most highly recommended spark plugs for GDI engines are the NGK Laser Iridium. You can get them cheapest on Amazon, just click this link and then choose the vehicle and engine you have.
Carbon Particulate Emissions are a less known common GDI problem
Although GDI engines are able to achieve better fuel economy and less CO2 emissions, they struggle mightily when it comes to what is called Carbon Particulate emissions.
This is due to the process in which fuel is ignited in the combustion chamber. I’m not sure that President Obama achieved his likely goal of reducing climate change when he enacted changes to the CAFE standards. The reason I say this is new studies show that black carbon emissions is becoming one of the biggest problems with GDI engines.
Black Carbon is known to cause cancer, birth defects.
Black carbon is created when the fuel being injected straight into the combustion chamber of a GDI engine is not entirely burned.
The result is less CO2 emissions, but far more black carbon. The list of nasty side effects of this particulate matter is long, but here are some of the more severe.
- Respiratory Diseases
- Cancer
- Birth Defects
Those are just the known health concerns presented by black carbon. It’s likely that humans in densely populated areas will be subjected more to the symptoms of black carbon pollution.
That doesn’t mean people in rural areas are out of the woods. That’s because particulate matter such as black carbon also has a pretty nasty effect on global warming according to most experts.
Black carbon is as the name suggests- Black. Because of this, it absorbs more radiation from the sun when released directly into the atmosphere causing a warming effect. It’s essentially the same effect that a Diesel engine has on the environment due to soot, which black carbon is considered to be.
Conclusion on GDI Engine problems
As you can see, there was a rush to adopt the GDI engine technology in the mid 2010’s due to the Obama administrations crack down on CO2 emissions.
Perhaps the EPA and other researchers did not envision the problems that would arise with this fairly foreign technology that had not been put into mass production.
The end result will be a significant debate and likely no real solution for the very near future. GDI engines have been adopted so rapidly that any attempt to scale back the production would prove difficult at best and impossible at worst.
It would seem that the problems created by the direct injected engine will be something consumers and manufacturers deal with for the foreseeable future. That is, until the Electric Vehicle becomes widely produced. At that point, automakers and researchers will struggle to find common ground there as well.
