7 Common Mazda 2.0 SkyActiv-G Engine problems – G122

We’ve recently talked about Mazda’s 2.5 SkyActiv petrol and their amazing little 1.5 SkyActiv-D engine. The next most requested engine by our readers was the 2.0 SkyActiv-G petrol engine. We’re used to seeing some stunning reliability records from Mazda, so we had our hopes high for this G122 Mazda engine.

Doing your homework before you decide to spend a ton of money on a car with a certain engine is always a good idea. You just don’t want to end up with a problematic engine that has a lot of different issues. And this is why we are here to pinpoint these problems for you.

First, we are going to learn the basic specs of the 2.0 SkyActiv-G engine and then we are going to cover all the Mazda 2.0 SkyActiv-G engine issues, as well as the models that carry this engine. So, let’s dive into it.

Basic Mazda 2.0 SkyActiv-G Engine Specs

The Mazda Skyactiv-G is an engine that was developed by Mazda in the mid-2000s. This engine succeeded the MZR engine that was previously in service.

Nevertheless, this Skyactiv-G is still based on its predecessor. But implements a lot of new upgrades and SkyActiv technologies that Mazda developed in order to maximize fuel economy and efficiency.

That’s what Skyactiv stands for in the first place. And honestly, they did pretty good work with this engine. It is far more reliable than the old rotary engines that they used back in the day and Mazda is finally picking up some traction once again in the market.

These are the specs of the 2.0 Skyactiv-G engine:

  • Year of Introduction: 2011
  • Configuration: inline-4
  • Displacement: 2.0L
  • Cylinder Bore Size: 83.5 mm
  • Piston Stroke: 91.2 mm
  • Block Material: Aluminum
  • Cylinder Head Material: Aluminum
  • Cylinder Head Design: DOHC, 4 valves per cylinder
  • Direct Injection: Yes
  • Aspiration: Naturally aspirated
  • Compression Ratio: 14.0:1 or 13.0:1
  • Horsepower: 155 – 162 hp
  • Torque Output: 150 – 154 lb-ft (200 – 210 N-m)

Common Mazda 2.0 SkyActiv-G Engine Problems

Common Mazda 2.0 SkyActiv-G engine problems include:

  • Intake Manifold Vacuum Leaks
  • PCV Valve Failure
  • Carbon Buildup On Intake Manifold
  • Carbon Buildup On Intake Ports
  • Low Oil Pressure
  • Intake Camshaft Failure
  • Engine Knock At Cold Start

Now that we covered the common Mazda 2.0 SkyActiv-G engine problems, let’s now move on and learn more about these issues in detail and see what could be causing these problems and also how they are represented.

We think that this is really important for you because in order to learn about the problem, you need to understand it. So, let’s dive into the issues.

Intake Manifold Vacuum Leaks

The intake manifold on these Mazda engines is not one of the strong points. But what is the intake manifold in the first place?

Well, the intake manifold is the component that is located on top of the engine. This intake manifold is directing air into the intake ports.

It is easily recognizable since it is a big plastic piece located on top of the engine right below the engine cover.

These SkyActiv engines are using rather complex intake manifolds and they tend to fail. They can crack or the gaskets that connect the intake manifold to the engine can leak.

Whenever this problem happens, you might get the check engine light and also experience problems such as engine misfires, lean air-to-fuel ratio, engine stalls, and low engine power.

The solution to this problem is to replace the intake manifold with a new one, or if the gasket is leaking replace the gasket.

Take note that this problem happens only on older high-mileage engines and not on newer ones. The older the engine, the bigger the chances for these gaskets to fail and leak air.

PCV Valve Failure

The PCV valve of this engine is another concern. So, what is a PCV valve in the first place and how does it work?

Well, the PCV valve is a special valve that is allowing the gasses from the crankcase to escape and not create problems in the engine.

As the engine works, there will be an increase in pressure inside the crankcase where the crankshaft is located. So, what this PCV valve does is purge the positive pressure out of the engine block.

This prevents oil leaks and other issues that can simply ruin the engine completely if the PCV valve is not properly working.

So, what can happen is that the PCV valve can fail and allow engine oil to get into the intake manifold and this will cause engine oil consumption.

So, if you notice that the engine is losing big amounts of engine oil. It is advisable that you address the PCV valve and replace it with a new one and install an oil catch can.

Other symptoms might include check engine light, low engine power, and oil leaks coming from the side of the engine.

Now let’s move on to the next Mazda 2.0 SkyActiv-G engine problems.

Carbon Buildup In The Intake Manifold

Another common problem with the 2.0 SkyActiv-G engine is the carbon buildup in the intake manifold.

As we noted previously, this engine has a problem with the PCV valve. The PCV valve is not doing its job particularly well and this causes a problem with excessive carbon buildup in the intake manifold.

The oil vapors enter the intake manifold and stick to the walls. Eventually, a lot of these carbon deposits will stick to the walls and create obstruction. In this case, the only way around the problem is to install a new intake manifold on your engine.

Carbon Buildup On Intake Ports

In addition to the carbon buildup in the intake manifold, there is also carbon buildup in the intake ports.

The intake ports are connected to the manifold. A bad PCV valve can also allow deposits to stick to the intake valve stems.

But there is also another problem. This engine uses direct injection. Direct injection is a new method of injecting fuel into the cylinders.

This way of injecting fuel makes the car more efficient. But one thing that does bad is the lack of cleaning on the intake valves. So, they become dirty and eventually will stop functioning properly.

The way around this problem is to do a method known as walnut blasting every 50,000 miles or so to clean off the carbon.

Low Oil Pressure

A problem with low oil pressure on this engine was also noted by a lot of owners and there is even a service bulletin on this problem.

What happens is that owners get the check engine light and DTC codes P0015 or P0524 indicating low oil pressure.

There is a recommended procedure for this problem when you go to the dealership. Usually, they delete the code and replace the engine oil and oil pump.

The pump is usually the problem specifically on the 2.0L engine if the oil pressure is not within specification.

If the oil pressure is according to the specs after measuring, they will not replace the pump. More on this you can read in the service bulletin that we attached.

Let’s move on to the next Mazda 2.0 SkyActiv-G engine problems.

Intake Camshaft Failure

On some engines, there was also wear on the intake camshaft that was noted. This is not a common problem with the 2.0 SkyActiv though.

Mainly because there are not a lot of complaints about this problem. But whenever there is wear on the camshaft, you will notice noises coming from the top of the engine.

The only solution unfortunately is to replace this component with a new one, since camshaft wear cannot be repaired.

Another thing to note is that this often occurs on engines that were poorly maintained and have often been left without a sufficient amount of engine oil.

It Is Noisy At Cold Start

And last but not least is the problem when you have engine noise at cold start. These Skyactiv-G engines tend to run pretty loud on a cold start.

So, if you hear some rattling noises, you should not be afraid since this is how these engines work until they reach the normal operating temperature.

More on this specific issue, you can check the video that we attached where all the sounds are explained.

Which Models Have The Mazda 2.0 SkyActiv-G Engine?

Now let’s see which models have the 2.0 SkyActiv-G engine:

  • Mazda 3
  • Mazda 6
  • Mazda CX-5
  • Mazda CX-3
  • Mazda MX-5


What are some common Mazda 2.0 SkyActiv-G engine problems?

The most serious problem with this engine is the PCV valve. It can fail and cause major problems like carbon buildup on the intake ports and intake manifold, also oil consumption. Another important problem that you should be aware of is the oil pump failure. Oil pumps tend to fail and cause low oil pressure. And it is quite a noisy engine, especially at cold starts.

Is The Mazda 2.0 SkyActiv-G Reliable?

Overall, the 2.0 SkyActiv is a really reliable engine. This engine can be pushed quite a lot, problems usually develop at around 150,000 miles (ca. 241,402 km) and these can include PCV valve failures, carbon deposits in the intake, and oil pump failures. But overall, it is a pretty good engine with a good reputation.

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