Honda 1.5 Turbo Engine Problems – Does It Have Oil Dilution?

Are you in the market for a used Honda and you don’t know what engine to choose? There are plenty of engines but the 1.5 looks the most appealing to you? You probably want to learn about the Honda 1.5 turbo engine problems. If that is the case, we are here to help you out and explain to you in-depth everything you need to know before you make a purchase.

• What Is The 1.5?
• 1.5 Applications
• 1.5 Engine Problems
• Is The 1.5 Reliable?
• Life Expectancy
• Final Conclusion
• FAQs

Doing proper research anytime you buy a used car is a great idea. Without proper research, you buy a car blindfolded and you don’t know what you are getting yourself into. On the market, there are hundreds of models that are out there. All these models have their weak points and strong points as well.

To make a good purchase, you have to learn all the strong sides and all of the downsides of each one of them. Knowing them will save you thousands of dollars in the long run.

Why I’m saying this? Although the car might seem in ok condition to you at first glance. There are still some factory defects that cars are prone to. And this is where you save money on possible future repairs.

In this article, we are going to cover everything you need to know when it comes to the 1.5 engine. We will learn the basics and then we will discuss the Honda 1.5 turbo engine problems. Then we will share our opinion on this engine. So, let’s dive in.

Honda 1.5 Turbo

The Honda 1.5 turbo engine is a small 4-cylinder engine that is produced by Honda from 2016 till the present day. This engine is the entry-level engine in their lineup of engines.

Every base car that Honda produces is equipped with these four-bangers. But mostly in the smaller cars that do not require a lot of power to run. We will go in-depth with the applications of the 1.5 in a bit but first, let’s discuss the 1.5 specs.

As we said the 1.5 is a four-cylinder engine that is equipped with a small turbocharger. With the help of the turbocharger, this 1.5 is producing 174hp. While the more tuned version of this engine with a bigger boost that is installed in the Civic Si is getting 205hp which is impressive for an inline-four engine.

This engine is of all-aluminum construction. This means that both the head and the block are manufactured from aluminum.

The engine is a dual overhead cam like most of Honda’s engines. The difference is that this engine is running a turbocharger. The turbocharger is rather small and also has some of Honda’s ingenuity in it that allows the engine to run without noticeable turbo lag which makes the 1.5 the perfect engine if you are looking for a small and fuel-efficient engine on the market right now.

As we said, the engine produces between 174 and 205hp and 162 to 192 lb. ft of torque. The more powerful versions are quite punchy and they are the way to go if you want an engine that is making a lot of power.

But what are the Honda 1.5 turbo engine problems? We are about to find out later in the article. But first, let’s learn more about how a turbo engine works.

Are Turbo Engines Reliable

Turbo engines work on the same principle as naturally aspirated engines but with a little twist (if you want to learn more, check out our write-up on what does naturally aspirated mean). And this twist is the turbocharger.

The turbocharger is a turbine that drives more air into the engine with the help of exhaust gases. This turbocharged forced induction system has gained traction in the last few years since this system makes the car more efficient.

This means with less displacement you get more power. Less fuel is spent on combustion since most of these engines are running direct injection as well.

Direct injection is quite different compared to multi-point injection because there are two fuel pumps and the fuel is driven with 2,200 psi of boost and this is a lot. And this is a drawback of these direct injection systems that we are going to cover later in this article when we are going to discuss the Honda 1.5 turbo engine problems.

These 1.5 engines are equipped with a smaller turbocharger and the lag is less noticeable. But what is turbo lag? Turbo lag is the delay from the point where you put your foot on the gas and the boost to kick in to spool the turbo. The bigger the turbo the more delay you have and lag in the process.

That’s why Honda uses this smart system to allow drivers to enjoy more in their vehicles more by reducing the turbo lag. Making this engine a popular choice among Honda buyers. But what about the Honda 1.5 turbo engine problems? We are going to cover the problems but first, let’s discuss the applications of this engine.

Honda 1.5 Turbo Engine Applications

The 1.5 turbo engine has found its way into many of the Honda products out there. Most notably in smaller applications since this engine is not a large displacement engine and doesn’t have the power to move some of their larger cars. But in which cars are the 1.5 most widely used?

Well, one of the top choices for the 1.5 turbos is the Honda Civic (to find out more, check out our explainer on are Honda Civic reliable). The Honda Civic is a small compact car that is made by Honda since 1972. This is probably Honda’s bestseller and the 1.5-liter in the Civic is also one of the bestselling engines.

Other applications include the CR-V which is a small crossover and one of the best-selling crossovers in the US.

This engine is also included in the bigger Honda Accord sedan. This engine is basically included in all lightweight vehicles that Honda produces because this engine delivers the best performance and fuel economy to the table.

But what about the Honda 1.5 turbo engine problems, are there any big issues with this engine? Well, we are about to find out in the next chapter.

Honda 1.5 Turbo Engine Specs

1.5 Turbo Honda Engine Specs
Technical Designation	L15B7
Cylinder Block Material	Aluminum
Cylinder Head Material	Aluminum
Fuel Used	Gasoline
Fuel System	Direct Injection
Cylinder Count	4
Cylinder Configuration	Inline-4
Valves Per Cylinder	4
Valvetrain Type	DOHC (Dual Overhead Camshaft)
Bore	2.87 inches (73.00mm)
Stroke	3.52 inches (89.50mm)
Displacement	1,498cc or 1.5-liter (91.4 cubic inches)
Aspiration	Turbocharged
Compression Ratio	10.6:1 or 10.3:1
Horsepower Output	174hp to 205hp (peak power at 5,500RPM to 6,000RPM, respectively)
Torque Output	162lb-ft to 192lb-ft (peak torque at 1,600RPM to 5,000RPM, respectively)
Firing Order	1-3-4-2
Engine Oil Type	SAE 0W-20
Oil Capacity	3.7 quarts (3.5 liters)
Oil Change Interval	Every 9,000 miles (15,000km) or 12 months
Applications	Civic, Civic Si, CR-V, Accord, (Acura) CDX, etc.

Honda 1.5 Turbo Problems

Now we came to the important part and that is the Honda 1.5 turbo engine problems. Like every other engine, the 1.5 turbo has some issues that you need to consider before getting one.

Most of these problems are by design and are shared among all of the 1.5 turbo engines and you need to pay close attention when you buy a used car with a 1.5-liter turbo. Are these problems a real deal-breaker? Let’s find out.

Honda Oil Dilution

This engine is famous for this problem. The fuel simply is finding its way into the oil and the oil and fuel mix with each other and create a mess. This will result in bad oil performance since the oil will lose the lubricating characteristics that allow it to lube the pistons and bearings.

Why this is happening? This problem is not caused by a factory defect but is caused by cold weather. And most of the 1.5 engines that are run in colder climates have this problem with Honda oil dilution.

This is caused because this engine is too slow in getting up to temperature. And some of the fuel is sticking to the cylinder walls. This fuel that is stuck on the cylinder walls is picked up by the rings on the pistons and then it goes into the oil. Then this gasoline dilutes the oil.

The most affected vehicles with this problem are the ones that are driven short distances in cold climates. Numerous drives like this and your oil get diluted. These engines are exposed to high risks of premature wear of the components.

This means that your engine will wear down pretty quickly if you don’t track the oil level and its condition. But what are the symptoms of oil dilution?

Symptoms Of Oil Dilution

There are a few symptoms that will help you out distinguish when you are experiencing a problem with oil dilution. Some of them are dead giveaways while some of them are not that clear to understand and can indicate other issues. So, which are they? Let’s find out.

1. Smell Of Gas When Checking The Oil Level

If you pull out your dipstick, you will notice how there is a smell of gas in the oil. This gas smell indicates that there is a problem (and forcing you to understand how to get gasoline out of clothes). Oil should smell like something burnt if it’s old. But it should never smell like gas.

2. Increased Oil Level

If the oil is diluted you will also experience an increased oil level. The oil level will be increased when you have this problem. This is because the oil is mixed with the gas. And if the oil is above max on the dipstick (and make sure you understand where the oil should be on the dipstick), then this is a clear sign that you have an engine that is mixing oil and gas.

3. Other Symptoms

Other symptoms when you have an issue like this may include engine stalling, misfires, and possible power loss caused by the excessive amounts of oil in the pan.

4. How To Avoid This Problem

The only way to avoid this problem if you live in a place where the climate is cold is to allow the engine to reach the proper working temperature. If you go to work in the morning let the engine run for a few minutes. That’s especially if your car struggles to start when the engine is cold.

Let it get up to temperature and then go to work. A few minutes should be enough, just in case you’re wondering whether do you have to warm up your car. Also, change your oil more frequently because the oil gets diluted and this oil is not good to use.

Changing the oil every 5,000 miles will be a good idea. Also, track your oil level more frequently and pay attention to the smell of the oil. If you sense gas then it’s a clear sign that you have an oil dilution problem.

Honda Earth Dreams Carbon Buildup

Carbon buildup is one of the most frequent downsides of this engine. But why there is carbon buildup specifically in this engine? This is because the engine is using direct injection.

Carbon buildup is one of the major flaws that these engines have and this is by design. Every direct-injection engine has a carbon buildup. Some of them are more while some of them are less prone to this issue.

This carbon buildup is usually created in the intake ports of the head. The carbon buildup can be so excessive that can even clog the intake ports completely and make them not seal properly. Which can result in rough idle and misfires in the engine.

Why is this happening? In port injection vehicles, the fuel is sprayed in a higher amount and at lower pressure. This basically works like an engine cleaner.

In direct injection cars, the gas is sprayed at 2,000 psi of pressure which turns the fuel into dust and this doesn’t act well since the oil that goes past the oil rings doesn’t have the time to be washed out from the cylinder walls. The end result is carbon buildup.

The carbon buildup usually starts to appear above 60k miles. Why above 60k miles? This is because the piston rings are starting to allow some oil to pass through at this point and the problem starts to appear. But what are the symptoms of carbon buildup in the 1.5 turbos? Let’s find out.

Symptoms Of Carbon Buildup

The symptoms of carbon buildup in the 1.5 engine are shared among all of the engines that are running direct injection. All these symptoms appear when there is an excessive buildup of carbon inside of the engines and this is most frequently after 100,000 miles.

If you have an engine like this, it is useful to know about this issue and give the engine some carbon cleaning. That we are going to discuss this after we cover the symptoms of carbon buildup. But which are these symptoms?

1. Engine Misfires

One of the first symptoms, when you have excessive carbon buildup, is an engine misfire. But how to notice that you have a misfire? This can be tricky since they can only be identified through listening. They usually sound like small bangs on the top of the cylinder.

Also, if you put your hand on the exhaust you will notice how there are pops of air when the car is idling. This means that the engine is misfiring badly. This symptom can be extremely annoying when you have excessive carbon buildup and an engine that was never cleaned.

2. Engine Idles Rough

When there are misfires in the engine you will also notice how the engine is running rough as well. You can notice this symptom pretty easily. You can hear how the engine is trying to keep up running.

The needle that is on the tachometer is moving up and down (basically, the RPM fluctuates while accelerating). This is because of the rough idle and the uneven work of the engine. This symptom can also indicate problems with the ignition.

But if you have one of these direct injection engines it is worth considering checking the carbon buildup in the engine as well.

3. Engine Hesitation And Loss Of Power

Engine hesitation (such as when your car hesitates when accelerating from a stop) and an increased loss of power will also be notable if the engine has a lot of carbon in it. The carbon will prevent the normal function of the engine and the valves will not seal properly.

This will result in low compression symptoms appearing and basically less power. You might lose even 50 to 60 horsepower from the engine. When the problem goes too far it may also destroy the valve and there will be no compression at all.

It is important to act quickly when you have power loss from the engine. This can be connected as well with bad ignition components. So, it is of great importance if you have this engine to consider the carbon buildup problem as well on your checklist of possible issues.

4. Damaged Spark Plugs

Spark plugs can also get damaged (this is crucial once you understand what do spark plugs do in your engine) because of this issue with the misfires but we are going to cover that in a separate chapter.

5. How To Clean Carbon

Fortunately, there is a method that is made for cleaning carbon from these direct injection engines. This method is called Walnut Blasting. How this works is pretty simple, the walnut material is put inside of the valves and is blasted with compressed air. This compressed air blows the carbon away from the valves.

There are also chemical solutions that are poured inside the valves. Then after a few minutes, this solution is sucked out from the valves with a vacuum and then the valves are nice and clean once again.

Both of these methods cost quite a bit to perform and you can expect to pay somewhere between $500 to $600 for this sort of work.

Spark Plug Problems

The spark plug problem with these engines is also worth noting. This problem is caused by two factors. One of the factors is the increased carbon buildup inside of the engine that covers the spark plugs with carbon and this results in damage to the spark plugs. So, it’s worth looking into what does a bad spark plug look like (and knowing how to tell if spark plug is bad).

Another cause is the increased spark plug wear on turbocharged engines. Engines that are turbocharged are quite known to wear spark plugs too often. It may, therefore, be necessary for you to learn how to check spark plugs regularly.

When the spark plugs are damaged, a few bad spark plug symptoms are starting to appear. They can be quite bad at times, such as seeing oil in the spark plug well or noticing oil on the spark plugs themselves. But what are the symptoms?

1. Bad Spark Plugs Symptoms

These symptoms are pretty much the same as the symptoms that occur when the engine is running with increased carbon buildup.

Most of these symptoms include engine misfires, engine hesitation, rough idle, and power loss.

2. How To Solve This Problem

The only way that you can solve this problem is by installing new spark plugs. Spark plugs on these engines usually last somewhere around 30,000 miles. That’s in case you’re wondering about how long do spark plugs last.

Replace them at this timeframe and you will not experience any issues with the engine. There are four spark plugs which cost around $10 each. Therefore, the total spark plug replacement cost isn’t too expensive (especially once you learn how to replace the spark plugs, and figure out how many spark plugs in a V8, as well as how to change spark plugs).

This job is also DIY-friendly and I would recommend it to anyone that wants to start wrenching on their car. Starting from simple things like this is key if you want to learn about mechanics. There is no better teacher than the real problem-solving experience that you get by doing things.

Honda 1.5 Turbo Engine Reliability

The 1.5 turbos is considered to be a reliable engine although there are some Honda 1.5 turbo engine problems that plague this engine.

These engine problems are not problems that are something too scary if the engine is properly maintained. And by this, I mean the engine needs to be walnut blasted and the intake ports cleaned on the head.

Also, spark plugs should be changed more frequently than other engines. Since by design these engines are going through spark plugs more often than other engines. And they are only four of them.

So, replacing them will not be a big issue for many car owners. You can even do this job at home using only a socket torque wrench and that’s it. You might even consider looking into platinum vs iridium spark plugs if you value longevity and performance. Or, be diligent about specific spark plug brands, such as NGK vs Denso.

Honda 1.5 Turbo Engine Lifespan

The life expectancy of this engine is fairly good and can last for more than 150,000 miles before major issues start to appear. If you follow the advice that we have listed above this engine can even last more than that with no problem.

When getting a car with this engine the best thing is to inspect the vehicle and see if the engine is good. Make sure that the engine pulls well and the transmission shifts properly. This will guarantee that the engine is good and you will not have major problems with the drivetrain.

Although, you never know what could happen with cars. But let’s hope for the best and that is carefree ownership. After all, the core engine itself is decently reliable and robust. Honda has also made some improvements in the following years since.

Facts: Honda 1.5T L15B7/Si Turbo Engine Specs, Problems & Reliability

1. The Honda 1.5L turbocharged engine is a result of Honda’s downsizing strategy that uses small displacement units with a turbocharger to provide fuel efficiency and decent power.
2. The engine features an aluminum open-deck cylinder block and cylinder head, lightweight steel connecting rods, and cavity-shaped pistons with plateau honing for reduced friction and increased operating efficiency.
3. The cylinder head has four valves for each cylinder and dual overhead cam (DOHC) driven by the timing chain, and the intake and exhaust camshafts are equipped with actuators of the VTC.
4. The engine has a mono/single-scroll turbocharger MHI-TD03 with small-diameter turbines and an electronic wastegate to minimize turbo lag effect and provide rapid response to acceleration.
5. The Honda 1.5L turbo engine uses a water-cooled exhaust manifold built into the cylinder-head, exhaust-port passages cast directly into the head, and a more common air-to-air intercooler to reduce the temperature of intake air.
6. The 1.5-liter turbo engine for the Honda Civic Si copies the European 1.5T VTEC Turbo engine specs and produces 205 hp at 5,700 rpm and 192 lb-ft (260 Nm) at 2,100 rpm.
7. The Honda CR-V and Honda Accord engines are based on the Si engine and have different compression ratios and boost pressures.
8. The most reported problem for vehicles with Honda 1.5L turbo engine is a high or rising engine oil level due to oil/gas dilution problem, which causes gas smells inside the cabin, a higher-than-normal engine oil level, check engine light, and engine misfires.
9. Short trips on a cold engine can cause carbon build-up on the backside of the intake valves, which is a problem of all engines with direct injection and no port injection.
10. The Honda 1.5L turbo engine has different modifications, including L15BF with a 10.6:1 compression ratio and L15B9 with a 179 hp (133 kW) power output, offered in the Chinese Market Acura CDX.

Honda 1.5 Turbo Engine Problems: In Conclusion…

In this article, we have covered a lot when it comes to the Honda 1.5 engine. We learned the specs of this engine and its displacement. Then we covered turbocharged engines and their benefits.

Then we focused on the main topic of this article and which is Honda 1.5 turbo engine problems. This engine is prone to some issues. These were the oil dilution that affected most of the engines that were running in colder climates. Also, the carbon buildup was caused by the direct injection system and the spark plug failing issue.

All these problems are not that serious and can be easily treated. Carbon should be cleaned more often and the engine should always get up to temperature before you drive off early in the morning to prevent oil dilution. Also, change the spark plugs more often if you want to avoid ignition issues.

FAQs On Honda 1.5 Turbo Engine Problems

If you’re still unsure about the Honda 1.5 turbo engine problems, our FAQs here might have the answers…

Honda Accord 1.5 Turbo Engine Problems

The Honda 1.5 turbo engine problems include its inability to heat up sufficiently while idling. In other words, it takes more time before the engine warms up enough, which can be a problem for those living in colder climates. In some cases, it won’t create enough heat until you start driving. Cold engines can cause condensation to appear, as well as produce excess fuel vapors. Altogether, that excess fuel could easily dilute the engine oil. Another downside of its direct-injection design is the carbon build-up on the intake valves. This is made worse when combined with that cold engine.

Honda Civic 1.5 Turbo Engine Problems

Just like the larger Accord, which has a higher tune of the 1.5 turbo engine, the Civic also suffers from similar issues. There’s fuel-oil dilution within the engine, which typically occurs in colder climates. The 1.5 turbo engine is so efficient, that it takes far too long to heat up. At this point, excess fuel vapors are left unburned, which stick onto the cylinder walls. This then gets picked up by the oil, which dilutes it. This oil dilution problem subsequently joins two other major issues. Firstly, the carbon build-up on the intake ports is quite severe. Additionally, the spark plugs could also get fouled pretty easily.

2021 Honda 1.5 Turbo Engine Problems

On the bright side, many of the Honda 1.5 turbo engine problems were solved as of 2021 and 2022. The primary issue with the 1.5 turbo engines was oil dilution, which caused other issues on its own. This is primarily due to how long it takes the 1.5 turbo engine to heat up, especially in colder weather. To solve this, Honda simply tweaked the ECU a tiny bit. This allowed the 1.5 turbo engine to run slightly richer from a cold start. And, Honda diverted some of the heat from the passenger cabin into the engine to help it heat up.

How Long Do Hondas Last

Hondas are one of the most robust and durable cars on earth. You can easily expect them to last upwards of 200,000 to 300,000 miles reliably. You could extend this even further with diligent care and servicing. In some cases, owners have depended on their Hondas for up to 20 years, and without significant issues compared to most other cars.

Did Honda Fix The Oil Dilution Problem For 2021

Unfortunately, despite a software tweak to help Honda’s engines heat up more (which is the main cause of oil dilution), this issue still persists in 2021. In particular, the 1.5 turbocharged Earth Dreams engines still suffer from oil dilution, even throughout 2021 and 2022. The only solution is for owners to change their motor oil more frequently before excessive dilution takes place. Some owners recommend swapping the oil every 3,000 miles or sooner.

How Long Do Turbos Last

Turbocharged engines – so long as you don’t modify and tune them excessively – usually last a long time. For example, many turbo-diesel trucks could easily last 250,000 miles before a rebuild of the engine is necessary. Some might even go upward of 500,000 miles and beyond. Similar concepts apply to regular passenger cars too, where turbocharged engines last just as long as naturally-aspirated engines. The only thing you need to be wary of is good maintenance to keep it running for a long time. That includes needing regular oil changes, using good motor oil, and ensuring that you practice a cool-down time – basically, letting the engine cool a bit after driving it before shutting down.

Is A 1.5 Liter Engine Good

When it comes to Honda’s 1.5-liter engines, they’re indeed pretty good. A smaller 1.5-liter displacement, especially when coupled with a turbocharger or two, can feature numerous benefits. With such a small motor, Honda was able to extract a good amount of performance out of it. Yet, it still retains the natural benefits of downsizing to smaller displacements. That includes lower emissions and improved fuel efficiency. In addition, Honda’s 1.5-liter engines, in particular, are generally rather reliable, with serious issues only cropping up sporadically. Thus, it’s the jack of all trades, offering a good mix of power, efficiency, and reliability.

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