5 Most Reliable Mercedes-Benz Engines Ever (+3 to Avoid)

In this article, we’re closely examining the top five most reliable engines that Mercedes-Benz has ever produced.

But it’s not all roses. Even among the best, a few have missed the mark.

To give you the full picture, we’ll also touch upon three Mercedes-Benz engines that unfortunately earned a less stellar reputation.

Let’s jump right in!

The 5 most reliable Mercedes-Benz engines

First, let’s discuss the five most reliable Mercedes-Benz engines ever made!

1. M113 (Most Reliable Mercedes-Benz Petrol Engine)

• Capacity: 4,266-5,439 cc
• Power: 275-574 hp
• Torque: 295-590 lb-ft
• Cylinders: V8
• Fuel: Petrol
• Common vehicles with this engine: Mercedes-Benz E 430, Mercedes-Benz S 500, Mercedes-Benz CLS 55 AMG

Let’s begin with a true stalwart – the M113.

The M113 is the most reliable Mercedes-Benz engine. Introduced in 1997, the M113 is a naturally aspirated V8 petrol engine that succeeded the M119.

It found a home in various Mercedes-Benz models, including the popular E-Class, S-Class, and SL-Class.

The engine came in various displacements, from a modest 4.3L to a powerful 5.4L in the AMG versions.

What set the M113 apart was its perfect balance of performance and durability.

The engine boasted up to 362 horsepower, offering an exhilarating driving experience. But power wasn’t its only strength. The M113 was designed with reliability at its core.

What makes the M113 so dependable?

Part of its charm lies in its simplicity. The M113 doesn’t rely on turbochargers or superchargers, reducing the number of parts that can fail.

Plus, its sturdy design and robust materials ensure it can handle the wear and tear of daily driving, even under harsh conditions.

Many M113 owners report that with regular maintenance and care, these engines can easily surpass 200,000 miles, a testament to their longevity.

So, if you’re in the market for a Mercedes-Benz with a petrol engine that has proven its reliability over time, the M113 is a stellar choice.

2. OM606 (Most Reliable Mercedes-Benz Diesel Engine)

• Capacity: 2,996 cc
• Power: 134-174 hp
• Torque: 155-243 lb-ft
• Cylinders: Straight-6
• Fuel: Diesel
• Common vehicles with this engine: Mercedes-Benz W124 E 300 D, Mercedes-Benz W210 E 300 Turbodiesel

Next up on our list is a diesel superstar, the legendary OM606.

Introduced in 1993, the inline-six OM606 is one of the most reliable Mercedes-Benz diesel engines.

The OM606, a successor to the OM603, has a solid reputation for its impressive durability and longevity.

The key to the OM606’s reliability is its straightforward mechanics. The OM606 doesn’t rely on complex systems that could lead to costly repairs, a common trait of many reliable engines.

However, it’s not just about what’s absent but also what’s present. The engine’s components are built to last. From the cast-iron block to the aluminum head, each part is robust and designed to withstand the test of time.

One of the most compelling aspects of the OM606 is its capacity to rack up miles without major issues.

With regular maintenance, it’s not uncommon to see these engines surpass 300,000 miles; some even claim to have reached the magical half-million mark!

3. M112

• Capacity: 2,398-3,724 cc
• Power: 168–255 hp
• Torque: 166–332 lb-ft
• Cylinders: V6
• Fuel: Petrol
• Common vehicles with this engine: Mercedes-Benz W210 E 280, Mercedes-Benz W202 C 280, Mercedes-Benz S 350

We now turn our attention to the M112, another one of Mercedes-Benz’s most reliable engines.

The M112 was introduced in 1997 and is an all-aluminum alloy V6 petrol engine. It’s found in various Mercedes-Benz models, including the C-Class, E-Class, and even the ML-Class SUVs, with displacements ranging from 2.6L to 3.7L.

A critical factor that makes the M112 so reliable is its construction.

The engine block is made of a high-strength aluminum alloy, while the cylinders are lined with silicon/aluminum, providing increased durability and heat resistance.

This robust construction helps the M112 withstand the rigors of daily driving and then some.

As with the previous engines, the M112 requires regular maintenance, but when well taken care of, it can easily run for several hundred thousand miles.

The engine has proven to be a reliable workhorse, providing a smooth ride and impressive longevity.

4. OM617

• Capacity: 2,998 cc
• Power: 80 hp
• Torque: 124 lb-ft
• Cylinders: Straight-5
• Fuel: Diesel
• Common vehicles with this engine: Mercedes-Benz 300D

Now, we have another diesel gem: the OM617.

Introduced in the 1970s, the OM617 is an oldie but a goodie. This turbocharged inline-five diesel engine is renowned for its exceptional reliability.

The OM617 was primarily installed in the W123 and W126 models, and it has gained a somewhat cult-like following due to its near indestructibility.

This engine might not be a power monster, but it is a longevity champion.

So, what makes the OM617 so tough? At its core, the engine’s robustness can be attributed to its simple and sturdy design.

The OM617 features a cast-iron engine block and cylinder head, which are more than capable of standing up to the rigors of high mileage and time.

Owners of Mercedes-Benz models with the OM617 often report that their vehicles can run for several hundred thousand miles, even over a million in some cases, with regular maintenance and no significant issues.

Related article: The 10 Most Reliable Mercedes-Benz Models And Years

5. M104

• Capacity: 2,799-3,199 cc
• Power: 190-276 hp
• Torque: 195-284 lb-ft
• Cylinders: Straight-6
• Fuel: Petrol
• Common vehicles with this engine: Mercedes-Benz W202 C 280, Mercedes-Benz W210 E 280

Rounding out our list of the most reliable Mercedes-Benz engines is the M104.

The M104, introduced in 1989, is an inline-six petrol engine that succeeded the M103. Found in various Mercedes-Benz models like the E-Class, C-Class, and SL-Class, it offered displacements ranging from 2.8L to 3.6L.

This engine is loved by many for its smooth operation and substantial power output, with the top-end versions capable of producing over 270 horsepower.

But it’s not just about power and performance with the M104; it’s also about reliability.

The M104 stands out thanks to its robust construction. The engine block is cast iron, while the cylinder head is made from aluminum, which ensures durability and longevity.

Regular maintenance is key to the M104’s longevity. When properly maintained, these engines can reach well over 200,000 miles without breaking a sweat.

Learn more: The 7 Best Mercedes-Benz Engines Ever Made

3 Mercedes-Benz engines to avoid

While Mercedes-Benz has crafted many exemplary engines, it’s also had a few misses.

Let’s check out some Mercedes engines that you may want to avoid if you’re concerned about reliability!

1. M156

• Capacity: 6,208 cc
• Power: 451–510 hp
• Torque: 465–479 lb-ft
• Cylinders: V8
• Fuel: Petrol
• Common vehicles with this engine: Mercedes-Benz E 63 AMG, Mercedes-Benz CLS 63 AMG, Mercedes-Benz C 63 AMG

Topping our list of engines to be cautious of is the M156, a V8 petrol engine introduced in 2006.

Developed by Mercedes-AMG, the company’s high-performance division, the M156 was the first engine built entirely by AMG.

At face value, the M156 appears impressive. Found in various AMG models, including the E63, CL63, and S63, this 6.2-liter V8 engine was celebrated for its incredible power output of up to 510 horsepower.

And for that, it’s seen as one of the best Mercedes V8 engines!

However, despite the thrilling performance, the M156 has shown to be prone to some issues.

One of the primary problems associated with the M156 is the premature wear of the intake and exhaust valve lifters, leading to a potentially costly repair. This issue is common enough that it led to a class-action lawsuit against the company.

Another well-known issue is the potential for head bolt failure, which can leak coolant into the combustion chambers. This can lead to serious engine damage and again, a hefty repair bill.

Despite its high-performance characteristics and exhilarating power, the M156’s various potential issues make it an engine to approach with caution.

If you’re considering a Mercedes-Benz AMG model with this engine, it would be wise to thoroughly check the vehicle’s history and maintenance records and be prepared for possible high-cost repairs down the line.

2. M272

• Capacity: 2,496-3,498 cc
• Power: 201-312 hp
• Torque: 181-269 lb-ft
• Cylinders: V6
• Fuel: Petrol
• Common vehicles with this engine: Mercedes-Benz W203 C 230, Mercedes-Benz C209 CLK 280, Mercedes-Benz W212 E 300

Next on our list of engines to approach with caution is the M272.

This V6 petrol engine was introduced in 2004, powering a range of Mercedes-Benz models, including the E-Class, C-Class, and SLK-Class.

While it offered good performance and power, it has been plagued by a notorious issue that tarnishes its overall reputation.

The main concern with the M272 is what’s known as the “balance shaft issue.” The balance shaft, or the gear that drives it, can wear out prematurely, leading to many problems. These can include rough running, loss of power, and check engine warnings.

Fixing the balance shaft issue is, unfortunately, not a minor task. The engine must be removed and disassembled, leading to a repair that can easily cost several thousand dollars.

Apart from the balance shaft problem, some M272 engines have also been known to experience issues with the timing chain and its tensioner, which can lead to significant engine damage if not addressed in time.

While the M272 provides a decent driving experience when running well, these potential issues make it an engine to think twice about.

3. M273

• Capacity: 4,663-5,461 cc
• Power: 335-382 hp
• Torque: 339-391 lb-ft
• Cylinders: V8
• Fuel: Petrol
• Common vehicles with this engine: Mercedes-Benz ML 450, Mercedes-Benz E 500, Mercedes-Benz SL 550

The final engine on our “to avoid” list is the M273, a V8 petrol engine introduced in 2005.

It found its home in a range of Mercedes-Benz models like the S-Class, CLS-Class, and GL-Class.

Much like the M272, the M273 has suffered from balance shaft gear failure. As this is an integral part of the engine, a failure can lead to serious issues, including rough running and loss of power.

Fixing this problem involves a significant amount of work, often necessitating the removal and disassembly of the engine, which can result in a substantial repair bill.

Another potential problem with the M273 involves the engine’s timing chain and tensioner. Failures in this area can lead to severe engine damage, adding another layer of potential high-cost repairs.

Additionally, the M273 has been known to suffer from problems with its idle gear and camshaft adjuster, which can also lead to expensive repairs.

If you’re considering a Mercedes-Benz model with an M273, ensure that the vehicle’s history has been thoroughly checked and any potential issues have been properly addressed.

Related article: 9 Common Causes Why A Mercedes Won’t Start (+ Solutions!)

Conclusion

As we wrap up this exploration of Mercedes-Benz engines, it’s clear that the automaker has produced some impressive and highly reliable engines over the years.

Models equipped with engines like the M113, OM606, M112, OM617, and M104 have proven themselves capable of delivering not just performance and luxury but also the kind of reliability that keeps them on the road for hundreds of thousands of miles.

At the same time, we’ve seen that not every engine in the Mercedes-Benz stable is a winner. Some, like the M156, M272, and M273, have been known to develop serious issues that can lead to costly repairs.

In the end, the key to a happy and long-lasting relationship with a Mercedes-Benz vehicle is regular maintenance and care, regardless of the engine it houses!