BMW N55 Engine Problems, Specs And Reliability!

BMW N55 Engine Problems, Specs And Reliability!

November 4, 2022 0 By CarGuy

Are you planning to purchase a BMW with the N55 engine and you are looking to find out more about the possible BMW N55 engine problems? Well, if that is the case, then you are at the right place because there will be quite a lot to cover on this topic.

Doing your own research before purchasing a car like a BMW should be one of your top priorities. BMWs are expensive to buy and also to maintain. So, when you are getting a new car, research is key in order for you to avoid ending up with a lemon.

This is why we are here to help you out with your trouble and help you understand more about the different issues that this engine has and also how difficult they are in order for you to overcome. Because not all problems are equal. Some are more expensive and some of them are rather easy to solve. So, what we are going to cover in this article?

First, we are going to introduce ourselves to the topic and learn more about the N55 engine basics. Then we will cover the N55 engine applications and see in which models this engine was included. After that, we will focus on the BMW N55 engine problems. We will elaborate thoroughly on some of the most common issues that owners have reported and give this N55 engine a reliability score. So, if you want to learn more, follow along.

What Is The BMW N55 Engine?

Now before we dive into the BMW N55 engine problems let’s take a look at the core concepts of the N55 engine and understand more about its background and why this engine is one of the most legendary engines that BMW has ever built.

So, when we think of BMW, we immediately connect the dots in our heads and think of performance. BMW since always strives for performance and luxury. And frankly, their cars are something that every car enthusiast wants to own at one point in their life.

But unfortunately, not all of us can afford the M3 or the M5. But what is good is that BMW got you covered. You don’t have to get the best in order to enjoy the performance that a BMW can offer.

And the N55 is one of these engines. Horsepower for the average Joe. And not only horsepower and performance but also reliability as well.

If you didn’t know, the N55 was an engine that was has won the Ward’s 10 best engine award for three years in a row from 2011 to 2013.

And that tells quite a lot about this engine. And not only that it got awards. This engine also proved itself in a lot of aspects. With good tuning, this engine could easily push 500 or 600hp. And 400+ is achievable even with a budget of $1,500. So, it is rather popular when it comes to car guys like me and you. But what about the BMW N55 engine problems? More on that, we are going to cover more in a bit, after we cover the applications of this engine.

BMW N55 Applications

Now before we discuss more about the BMW N55 engine problems, let’s take a look at the applications in which this engine was included. And frankly, there are a lot of cars where you can find this engine in. So, let’s cover them really quickly. What is worth noting is that there are a few variations of this engine. Namely, the N55B30M0, N55B30, N55B30O0, N55HP, and N55B30T0.

Let’s start with the N55B30M0:

Cars:

  • 2010 – 2013 BMW E90/E91/E92/E93 335i
  • 2009 – 2013 BMW F10/F11/F07 535i
  • 2010 – 2013 BMW E82/E85 135i
  • 2013 – 2016 BMW F32/F33/F36 435i

SUVs:

  • 2012 – 2015 E84 BMW X1 xDrive35i
  • 2010 – 2017 F25 BMW X3 xDrive35i
  • 2014 – 2016 F26 BMW X4 xDrive35i
  • 2011 – 2013 E70 BMW X5 xDrive35i
  • 2014 – 2018 F15 BMW X5 xDrive35i
  • 2011 – 2014 E71 BMW X6 xDrive35i
  • 2014 – 2019 F16 BMW X6 xDrive35i

N55B30 Was included only in cars:

  • 2013 – 2013 E82/E88 BMW 135is
  • 2012 – 2015 F20/F21 BMW M135i
  • 2011 – 2018 F06/F12/F13 BMW 640i
  • 2012 – 2015 F01/F02 BMW 740i

N55B30O0 was a high-performance engine included in the following models:

  • 2015 – 2016 F20/F21 BMW M135i
  • 2013 – 2016 F22/F23 BMW M235i

N55B30T0 was another high-performance engine included in the following models:

  • 2016 – 2018 F87 BMW M2
  • 2015 – 2018 F26 BMW X4 M40i

N55HP was a hybrid version of the N55 engine included in the following models:

  • 2011 – 2016 F10 BMW 5 Series ActiveHybrid 5
  • 2013 – 2015 F30 BMW 3 Series ActiveHybrid 3

But what about the BMW N55 engine problems? Well, more about the problems we are going to cover in a bit after we complete the rest of the specs of this engine.

BMW N55 Engine Specs

Now as we cleared the applications in which this engine was included. Now we can slowly move on and learn more about the N55 engine specs. Let’s take a look at the main characteristics of this engine and understand more about it before we dive into the BMW N55 engine problems.

The important thing when it comes to this engine is that this engine is an inline-6 engine. So, what does this mean? This means that the pistons are laid out in a straight line, all six of them. Unlike V6 engines where the pistons are laid out in a V-pattern.

The N55 engine block and the head are made of aluminum. Making this engine quite lightweight compared to other engines in its class.

The piston stroke is 3.53 inches and the bore of the cylinders is 3.3 inches. As you can see, this engine has a longer stroke than the bore and this allows this engine to create more torque at lower RPMs.

The head design is a double overhead camshaft (DOHC) like all modern engines. The cylinder head has four valves per cylinder with 24 valves in total. 2 valves are for the intake and two valves are for the exhaust. The engine has variable valve timing. And the redline RPM is about 7,000 RPM. Which is quite good for high-performance applications

And another good thing about this engine is that it is turbocharged. This engine uses a single Borg Warner B03 Twin Scroll turbocharger. The ECU used on this engine is the Bosch MEVD17.2. But what about the N55 engine problems? More on that we will cover in a bit.

BMW N55 Engine Horsepower

So, we learned the specs of this engine, now before we cover the BMW N55 Engine problems, let’s take a look at how much power is this engine making.

When it comes to power, it is worth noting that this engine is rated differently for each application. For example, the N55B30M0 creates about 302hp and 295 lb-ft of torque.

The N55B30 and B55B30O0 create 315hp and 322hp respectively. The torque number is the same for both engines. 332 lb-ft.

The N55B30T0 is the highest-performance N55 engine. This engine creates between 355hp and 343 lb-ft of torque and 365hp 369lb-ft of torque depending on the application. But what about the BMW N55 engine problems? More on that we will learn in a bit

BMW N55 Engine Weight

Before we learn more about the BMW N55 engine problems, let’s take a look at what is the engine weight of the N55.

This engine is quite lightweight. It only weighs 290lbs or 132 kg.

BMW N55 Engine Oil Capacity

Another thing that we would like to cover before we learn about the BMW N55 engine problems is the oil capacity of this engine.

The oil capacity of the N55 is 6.9 quarts of 6.5 liters. The recommended oil viscosity is 5w30 or 5w40. 5W40 is a better alternative because this engine by spec should burn about 1 quart of oil per 850 miles.

So, using thicker oil will guarantee that the engine does not burn as much oil. Also, doing your oil changes more regularly will guarantee that your engine does not burn as much oil as well. But what about the BMW N55 engine problems? More on the problems next.

BMW N55 Diagram

Another thing that we would like to cover when it comes to the N55 before we learn more about the BMW N55 engine problems is the engine diagram.

We will show you a video of an N55 engine build so you can introduce yourselves to this engine and visualize the components inside. And next, we are going to cover the BMW N55 engine problems.

BMW N55 Engine Problems

We covered the specs of the N55 engine. And we think that now it is time to dive even deeper and learn more about the BMW N55 engine problems.

Knowing the problems that this engine has, will help you prepare in case something happens and make sure that you are completely aware of its downsides since nothing is perfect. So, let’s cover the BMW N55 engine problems.

1. Oil Leaks From The Valve Cover

Now let’s begin discussing the BMW N55 engine problems. The first problem on our list is the problem with oil leaks coming from the valve cover. So, what is a valve cover?

Well, the valve cover is that big plastic cover located on top of the engine. This cover basically covers the valvetrain and the camshafts of the engine.

And what is important in this case is that the valve cover has to seal well in order for you to avoid possible problems with vacuum leaks and also oil leaks. So, why there are vacuum leaks and oil leaks?

Well, both of them are a consequence of a bad valve cover gasket. A vacuum leak is considered to be any unmetered air that is entering the engine. While the oil leaks are considered to be the leak of oil that sips from the side of the engine where the valve cover and the cylinder head come into contact.

And both of these situations are bad. For example, when you have vacuum leaks, you will have a problem with the check engine light and there will be codes concerning the PCV system.

On the other hand, when you have oil leaks, you could have a greasy engine, a burning smell, oil in the spark plug holes, as well a low engine oil level that could damage the engine. So, you get the idea why these BMW N55 engine problems are really important to solve. If you notice a leak, replace the valve cover gasket and make sure that there is no oil. Now let’s move on to the next BMW N55 engine problems.

2. Oil Leaks From Oil Filter Housing Gasket – BMW N55 Engine Problems

The second on our list of BMW N55 engine problems is the oil leak from the oil filter housing gasket.

If you didn’t know, this engine implements a rather strange design. It has an oil cooler right to the oil filter housing gasket.

So, the oil cooler and the oil filter housing are directly connected and between them, there is a rather thin rubber gasket that is in charge to do all this work and seal well.

And what can happen is that this gasket can fail and oil will start to leak. This is a fairly common problem. Especially on the earlier N55 engines.

And in order to get the job done, you need to drain the oil and also drain the coolant for a little thin gasket. How the procedure is done, you can check out in the video. Now let’s move on to the next BMW N55 engine problems.

3. Charge Pipe And Boost Pipe Detaching From Throttle Or Intercooler

The next in our list of BMW N55 engine problems is the failure of the charge pipe and boost pipe. These pipes simply detach and you lose the turbo. So, why is this the case?

First and foremost, what is important to note is that this problem is fairly uncommon on engines that are not tuned. So, if your engine is running on factory specs and not running on higher boost, you will probably not going to experience it ever while owning the N55.

But if you consider increasing the boost of the turbo or upgrading the turbo, then upgrading these components as well is rather essential in order for you to avoid failures on the charge pipe and the boost pipe. Now let’s move on to the next BMW N55 engine problems.

4. Water Pump Failure – BMW N55 Engine Problems

The next in our list of BMW N55 engine problems is the water pump failure. So, why a water pump failure? Is this problem common?

Well, as we did our research, this problem is rather common. Namely, the N55 is using an electric pump that is driven with the help of a composite impeller. And this could be the factor that these water pumps do not have a long life.

The thermostat is also one very common problem on these engines. So, when you do the water pump, it is highly recommended that you also do the thermostat job as well.

When these water pumps go out, they usually do not show symptoms at all. So, at one point you have a properly working water pump, and the next moment your BMW overheats. So, when you run this engine, it is really important that you put an eye on the temperature gauge when you do some long-distance driving.

When these problems occur, you will have the engine overheating quite significantly, as well as the cooling fan spinning at full speed. Not to mention the boiling coolant and the system that will try to release the pressure from the expansion tank.

This overheating issue could also lead to a head gasket failure. So, if you don’t detect the problem on time, it could result in a very expensive repair. Now let’s move on to the next in our list of BMW N55 engine problems.

5. VANOS Solenoid Failing

The next problem in our list of BMW N55 engine problems is the VANOS solenoid failure. So, what is VANOS?

If you didn’t know BMW wants to call their variable valve timing setup with the VANOS name. So, essentially VANOS is variable valve timing. But what is variable valve timing?

Well, variable valve timing is a special system that is installed on the camshafts of the engine. This system has a special role in the work of the engine. Depending on the engine work, it is able to advance or retard the position of the camshaft in relation to the crankshaft.

In other words, the engine, through the computer can manipulate the engine timing. And this is done hydraulically.

Basically, the engine oil serves as a hydraulic fluid to power the variable valve timing| (VANOS). And there is also an electrical component that is known as a solenoid.

The solenoid is simply a switch that is activated by the engine and this switch activates the VANOS. And in this case, when the VANOS solenoid fails, it means that this switch is out of use.

And when this happens, you basically don’t have variable valve timing. This situation can result in a number of symptoms. Namely, loss of power, hesitation, rough idle, limp mode, and even engine stalling in some cases.

This is why it is important to learn about the problem and replace this solenoid in order to solve the issue. Now let’s move on to the next BMW N55 engine problems.

6. High-Pressure Fuel Pump Failing (HPFP) – BMW N55 Engine Problems

Now let’s move on to the next BMW N55 engine problems. And this next problem is a pretty expensive one. Namely, a failure with the high-pressure fuel pump (HPFP). But what is a high-pressure fuel pump?

A high-pressure fuel pump is the secondary fuel pump that your BMW has. The first low-pressure fuel pump is in the tank and the second is somewhere along the fuel line.

The need for two fuel pumps is there because these engines use direct injection. Direct injection is a system that requires fuel to be basically atomized. So, the pressure the secondary fuel pump has to deliver is enormous.

This system makes the complexity of the engine a lot bigger. But what is good is that this pump that is prone to problems was usually installed on the earlier models of the N55. Newer engines have better fuel pumps. This is why we would recommend going for a later model year of this engine in order to avoid this problem. Now let’s finish with the last in our list of BMW N55 engine problems.

7. Factory Fuel System Not Capable Of Pushing Past 500hp

And the last in our list of BMW N55 engine problems is the problem with the fuel system when it comes to boosting the engine.

We investigated the matter and we learned that this factory fuel system is not good enough when it comes to tuning the engine.

A little bit of tuning is good, let’s say up to 500hp. But if you plan to tune the engine further and push the boundaries, you will also have to do some fuel system upgrades on the N55 engine as well.

BMW N55 Reliability

We covered the BMW N55 engine problems, now let’s take a look at the overall reliability of this engine. Is this a reliable engine?

The short answer is yes. This engine when it comes to the block and the cylinder heads is basically bulletproof and is able to be pushed a lot higher than the factory tune. These engines can easily make 500 or 600hp.

The drawbacks of the engine are mostly connected to some of the components mounted to it. Namely, the water pump, secondary fuel pump, VANOS solenoid, valve cover gasket, and oil housing gasket.

These are the issues. Are they a deal breaker? Well, no, they are not a deal breaker and we could easily give this engine a 4.5/5 score. When it comes to buying a car with this engine, just try to avoid the early model years. Just in case not to end up with the failing high-pressure fuel pump.

Conclusion To BMW N55 Engine Problems

In this article, we have covered quite a bit when it comes to the BMW N55 engine problems. First, we learned more about the N55 engine and its specs and applications of this engine.

Then we focused on the BMW N55 engine problems. We have covered all 7 most common problems that this engine has. And lastly, we discussed the N55 engine reliability and we gave the engine a reliability score.

If you think that we missed something, don’t be shy to add it in the comments below.