The 3 Most Common Mercedes M113 V8 Engine Problems

In 1997, Mercedes unveiled the M113 engine family. There are four engine options: a 4.3-liter, 5.0-liter, 5.4-liter, and a 5.4-liter supercharged version. With a range of 275 to 574 horsepower, this car packs a punch considering its age. The M113 is regarded by some as one of the best engines made by the company.

It’s important to remember that no engine will ever be faultless, and this is no exception. We’ll talk about Mercedes M113 engine issues and reliability in this article. The M113 V8 engines are also discussed in terms of performance, spec, and general knowledge.

M113 Engine Variants

M113 Engine Variants

Depending on the model, the M113 comes in a variety of engine sizes. They are all based on the same basic design. In the following section, we’ll go over the specifics of the M113 engine, but first, let’s cover the essentials.

4.3L M113 Engine

In the M113 family, this is the tiniest engine. It has a 4.3 liter displacement thanks to its 89.9mm x 84mm bore and stroke. In terms of power, the car has 275 horses and 295 pound-feet of torque. The 302hp and 302lb-ft of torque on the C43 AMG models are a welcome addition. Models with Mercedes-Benz M113 4.3L engines include:

  • 1998-2000 C43 AMG
  • 1998-2002 E430
  • 1998-2003 CLK430
  • 1999-2001 ML430
  • 1999-2006 S430

Mercedes M113 5.0 Engine

The 97mm bore and 84mm stroke are standard on M113 5.0L engines. One thing to keep in mind: The bore is larger, but the stroke is identical to that of the smaller 4.3L engine. The engine develops 302 horsepower and 339 pound-feet of torque. Mercedes-Benz uses it in the following models:

  • 1998-2008 G500
  • 1999-2006 S500
  • 1999-2006 SL500
  • 2000-2006 CL500
  • 2001-2006 ML500
  • 2002-2006 CLK500
  • 2003-2006 E500
  • 2004-2006 CLS500
  • 2006-2007 R500

5.4L NA M113

The M113’s largest engine is the 5.4. It has the same 97mm bore as the 5.0, but a 92mm stroke. With 342-362 horsepower and 376-391 pound-feet of torque, this engine blows away the competition! Excellent performance for a naturally aspirated engine from the late 1990s. The M113 in the SLK 55 AMG Black Series is also tuned to 396 hp. The following 55 AMG models are powered by M113 5.4-liter V12 engines:.

  • 1998-2000 C55 AMG
  • 1998-2001 SL55 AMG
  • 1998-2002 E55 AMG
  • 2000-2002 S55 AMG
  • 2000-2003 ML55 AMG
  • 2000-2006 CLK55 AMG
  • 2001-2002 CL55 AMG
  • 2002-2003 G55 AMG
  • 2004-2010 SLK55 AMG
  • 2006-2008 SLK55 AMG Black Series
  • 2005-2007 C55 AMG

There are numerous supercharger kits on the market that deliver similar performance and results to the M113K.

Supercharged 5.4 M113K

The Mercedes M113K engine, also known as the M113 5.4 Kompressor, is the last but not least. While it’s a new engine, it’s identical in displacement to the previous NA 5.4L.

Adding a supercharger and twin intercoolers raises the performance of this engine to another plane of existence. The range of power and torque is from 469 to 574 hp and 516 to 590 lb-ft, respectively. Mercedes-Benz uses the M113K supercharged engine in the following models:

  • 2003-2006 CL55 AMG
  • 2002-2006 S55 AMG
  • 2002-2008 SL55 AMG
  • 2003-2006 E55 AMG
  • 2004-2006 CLK DTM AMG
  • 2004-2011 G55 AMG
  • 2004-2006 CLS55 AMG

Mercedes M113 Engine Specs

Engine Mercedes M113
Displacement 4.3L, 5.0L, 5.4L
Configuration V-8
Aspiration NA (M113K supercharged)
Bore x Stroke 89.9mm x 84mm (4.3L), 97mm x 84mm (5.0L), 97mm x 92mm (5.4L)
Compression 9.0 : 1 to 11.0 : 1
Valvetrain 3 valves per cylinder (2 intake, 1 exhaust)
Block/Head Material Aluminum
Horsepower 275-574hp
Torque 295-590 lb-ft

Dimensions such as size, bore x stroke and compression ratio differentiate the engines. However, there are a few notable differences between the standard M113K and the supercharged version. We’ll come back to this subject shortly. 4.3-liter engines share the same basic architecture and design as 5.0- and 5.4-liter engines. Each cylinder has three valves and is built with an aluminum block and cylinder head.

Forged connecting rods, cast camshafts, and a magnesium intake manifold are also standard on all engines. The M113 engine’s relative simplicity is appreciated by some. It was created prior to the widespread use of VVT. For their age, Mercedes M113 engines produce impressive power and torque despite their simplicity.

M113K Differences

Previously, we discussed the option of installing a supercharger kit on a 5.4L V8 Mercedes engine. However, compared to the NA 5.4 engine, the M113K has a slew of improvements. It’s not uncommon for aftermarket upgrades to help support the supercharger’s increased power and performance. There are several improvements to the 5.4 Kompressor engine.

Mercedes also improved the engine’s flow and increased the engine’s redline with some head work. To put it another way, simply adding a supercharger to the 5.4L M113 doesn’t transform it into a true M113K.

3 Common M113 Engine Problems

Common M113 Engine Problems

The Mercedes M113 engine has a number of common problems, some of which are listed below:

  • Rear main seal
  • Intercooler pump
  • Spark plugs

In the following paragraphs, we’ll go into greater detail about the aforementioned M113 issues. Prior to moving on, it’s a good idea to add a few notes. These are some of the more common issues, in our opinion. But just because they’re common doesn’t mean they’re really common. In other words, when something goes wrong or fails, these are some of the common places where it can go wrong.

Despite this, many people regard the M113 engines as simple and dependable. However, one’s age plays a significant role. The Mercedes M113 engines in use today are well into their second decade, if not already in it.

When you’re that old, you have to wonder about things like dependability and longevity. We’ll talk more about overall M113 reliability at the end of the piece. Instead, let’s consider the problems with the M113 V8 engines listed above.

1) Mercedes M113 Rear Main Seal Leaks

First, there’s a problem with the 4.3, 5.0, and 5.4L Mercedes V8 engines that’s directly linked to their age and mileage. Oil leaks are a common problem with old vehicles and engines. Seals and gaskets made of rubber degrade and crack over time. The M113’s rear main seal is a perfect example of this.

The crankshaft’s connection to the transmission is sealed by the rear main seal. Once a crack forms, the oil starts leaking out of the device. When it first starts, it’s usually a small leak that gets worse and worse over time. As a result, leaks in the M113 rear main seal aren’t a serious issue. Even so, you should replace the rear main seal as soon as you notice an oil leak.

Due to labor costs, this is a costly issue. As Mercedes M113 V8 engines get older, it’s more common to have leaks around the main seals. If you’re thinking about buying one of these vehicles, make sure to look into whether or not it has been recently replaced. If you don’t, it’ll be a problem you have to deal with sooner rather than later. Also, as these engines get older, other oil leaks like leaking valve cover gaskets become more common.

4.3, 5.0, 5.4L Rear Main Seal Symptoms

When the M113’s rear main seal leaks oil, the following symptoms occur:

  • Visible oil leak
  • Oil loss

The most likely symptom is visible leaks on the ground near the back of the engine bay. In many cases, it’s the only thing you’ll notice. It’s possible that if the leak is severe enough, you’ll notice that the Mercedes V8 is using more oil than usual. If there is a serious leak, you should have noticed it much earlier.

Light smoke and burning oil odors can be symptoms of other leaks, such as valve cover gasket leaks. This is not always the case with a rear main seal, as oil drips to the ground instead of hot components.

M113 V8 Rear Main Seal Replacement

A leaking rear main seal necessitates the removal of the transmission. Since the average work week is around 7-10 hours long, the cost of labor alone can range from $700 to 1000 or more.

For the most part, the replacement part will only cost you around $20. It’s a difficult task, and you’ll need specialized equipment to complete it. Rear main seal replacement on the M113 or M113K should only be attempted by highly skilled do-it-yourselfers.

2) M113 5.4 Kompressor Intercooler Pump Problems

The Mercedes M113supercharged K’s 5.4-liter engine is the only one with an intercooler. As a result, only engines with greater output are affected by this problem. Charge air is cooled using an intercooler system (pressurized air). In the absence of it, the intake air temperatures (IATs) soar, causing the computer to shut down the supercharger.

The M113 intercooler pump has failed, and that’s the problem right now. If the original IC pump fails, there is an updated Bosch 010 pump that you can use instead. For those who run higher boost and power, aftermarket options are also an excellent idea.

When the intercooler system is inefficient at higher boost, it’s not uncommon for an IC pump to be mistakenly replaced. Increasing the boost pressure generates more heat, and the stock intercoolers may be quickly exhausted as a result. When tuning or otherwise modifying the Mercedes 5.4 Kompressor, take this into account.

Mercedes 5.4L IC Pump Symptoms

The following are some signs that the Mercedes M113K engine’s intercooler pump may be failing:

  • Power loss
  • Supercharger shutting down
  • High IAT’s

Intercooler system capacity is reduced or shut down completely when the pump fails. As a result, IATs go up, which leads to subpar results. Boost and timing will be reduced as the temperature rises to prevent knocks. Computer shuts down supercharger if IATs become too hot.

Once again, these are signs that your intercooler is overtaxed, so keep an eye out for them. If you have mods installed, you may want to think about adding an intercooler or other types of cooling equipment.

M113 V8 IC Pump Replacement

New Bosch 010 parts are available here. If your original M113 Kompressor intercooler pump fails, this aftermarket replacement costs just a little more than $150. This pump has a better flow and appears to be more dependable than the previous models I’ve used.

A repair shop’s labor is likely to be a couple of hours long, so budget on an additional fee. Anyone who knows their way around an engine can easily complete this do-it-yourself project. Here’s a quick video showing how to replace the M113 IC pump.

3) Mercedes M113 V8 Spark Plugs

Since spark plugs aren’t a real issue, we’ll move along quickly through this section. Most engines, including the Mercedes M113, require regular replacement of their spark plugs. However, the V8 engine uses two spark plugs per cylinder, so it’s worth mentioning. In fact, there are 16 spark plugs in total in this engine.

This serves as a good reminder of some of the benefits of investing in high-performance engines. Owning and maintaining these vehicles can be more expensive, even if they are dependable. Spark plugs, on the other hand, are subject to normal wear and tear and are critical to a vehicle’s operation.

A car with 16 spark plugs is ripe for problems. Although premature failures are rare, they do occur. Moreover, the M113increased K’s power means that spark plugs will be used up much more quickly. To put it another way, increasing the boost increases the cylinder pressure, which in turn stresses the ignition system. Spark plugs, despite their simplicity, should not be ignored.

MBZ M113 Spark Plugs Symptoms

The Mercedes-Benz V8 engine may exhibit the following symptoms if its spark plugs are old and faulty:

  • Power loss
  • Rough idle
  • Stuttering/hesitation
  • Misfires

When the spark plugs wear out, the air/fuel mixture in the cylinder can no longer be fully ignited. Misfires are common on the M113, and any one of them can indicate a host of other drivability issues.

Loss of power is a possible symptom, but unless multiple cylinders are misfiring, it is often difficult to notice on a V8 engine. Stuttering when accelerating and a rough idle are both common symptoms.

Spark Plug Replacement

M113 spark plugs typically cost between $90 and $125 for a complete set. Overall, it’s not too expensive, but the cost of a new spark plug in many other cars is double the price of this one. Every 50,000 to 80,000 miles, the spark plugs should be replaced.

In contrast, the Mercedes M113 5.4 Kompressor is more likely to deplete its supply of spark plugs more quickly. Changing spark plugs is a simple task that most people can handle on their own in the garage or driveway.

Mercedes M113 Reliability

Mercedes M113 Reliability

Is the Mercedes-Benz M113 V8 engine a dependable powertrain? Yes, we believe the reliability of this engine ranges from average to above average. It helps reliability a little that the M113 is simpler than newer engines. However, the passage of time is not on its side.

As engines get older, more maintenance becomes necessary. Mercedes-Benz V8 engine oil leaks, particularly from the rear main seal, are becoming more common. The 5.4-liter M113K is more difficult to maintain due to its higher boost pressure. The intercooler pumps on the engine are also a source of failure.

It doesn’t matter which way you look at it, the M113 is still a solid and dependable powerplant. Given the age, it’s critical to find a well-maintained example. Many of the problems that M113 owners face are the result of their own negligence.

Make sure to use high-quality oils, keep up with fluid changes, and address issues as soon as they arise. If you do all of these things, the M113 V8 will serve you well for a long time.

M113 Engine Problems Summary

The M113 engines were first used in Mercedes-Benz models in 1998. There are four engine options to choose from: 4.3L, 5.0L, 5.4L NA, and a 5.4L supercharged. For their time, all of these engines were capable of great things. The most powerful engine is the 5.4 Kompressor, but owning one can be more difficult due to its higher performance requirements.

In any case, the M113 engine in all its forms offers excellent reliability. As these engines get older, oil leaks become more common. The intercooler pumps have been known to fail on the Mercedes M113 Kompressor.

Otherwise, we talked about spark plugs to emphasize the fact that high-performance engines can be more difficult to maintain on a routine basis.

The most important thing is to find an example that has been well-kept and is clean. Engines can still be very dependable even if they are decades old and well-maintained.

What are your thoughts on the Mercedes-Benz M113 powertrain? Let us know what you think by leaving a comment below!

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