The Most 4 Common Mercedes M272 Engine Problems

Most Common M272 Engine Problems

Mercedes-M272 Benz’s V6 engine is intended to replace the M112 V6 engine. Mercedes’ previous six-cylinder engines were all straight sixes. It is available in a variety of Mercedes models from 2004 to 2015 with a 2.5L, 3.0L, or 3.5L displacement. This article will discuss common M272 engine problems, their symptoms, and how to resolve them.

Mercedes-Benz M272 Engine

Prior to delving into M272 engine failures, we’ll review the various M272 engine models. This is a lengthy list. Additionally, certain years or models may be more or less prone to the issues discussed.

E25 2.5L M272 Engine

The M272 2.5L is available in the following Mercedes-Benz models:

  • 2005-2007 W203 C230
  • 2007-2009 W204 C230
  • 2005-2009 W211 E230
  • 2008-2011 CLC230

E30 3.0L M272 Engine

Mercedes-Benz offers the following models with the 3.0L M272 engine:

  • 2004-2010 SLK280
  • 2005-2010 W219 CLS280
  • 2005-2010 C209 CLK280
  • 2005-2007 W203 C280
  • 2007-2009 W204 C280
  • 2009-2011 W204 C300
  • 2008-2012 GLK300
  • 2005-2009 W211 E280
  • 2009-2011 W212 E300
  • 2005-2009 R230 SL280
  • 2007-2013 W221 S280

E35 3.5L M272 Engine

At 3.5L, this is the largest M272 engine available, producing 268-302 horsepower. It resides in the following Mercedes-Benz models:

  • 2004–2011 SLK350
  • 2004–2010 W209 CLS350
  • 2005–2010 C209 CLK350
  • 2005–2007 W203 C350
  • 2007–2011 C350 / C350 4Matic
  • 2011–2015 C350 BlueEfficiency
  • 2005–2009 E350 / E350 4MATIC
  • 2009–2011 E350 / E350 4MATIC
  • 2005–2013 W221 S350
  • 2005–2012 R230 SL350
  • 2006–2017 R350
  • 2006–2011 W164 ML350
  • 2008–2011 CLC350
  • 2008–2012 GLK350

Mercedes-Benz M272 Engine Problems

Mercedes-Benz M272 Engine

The following are four of the most frequently encountered issues with the Mercedes M272 engine:

  • Balance shaft
  • Intake manifold
  • Thermostat
  • Oil leaks

Simply because these four issues are among the most prevalent does not mean that every M272 will experience them. Additionally, many M272 engines are more than a decade old. As is the case with any aging engine, a slew of potential issues become apparent.

You may encounter issues not addressed in this article. Anyway, let’s dive in and discuss each of the M272 issues listed above.

1) Mercedes M272 Balance Shaft Problems

This issue is likely deserving of its own post. Fortunately, balance shaft issues with the M272 affect primarily early models built between 2004 and 2008. The M272 engine, like the majority of V8 engines, has a 90° V angle. This, however, results in an excessive amount of vibration. Mercedes equipped the M272 with a balance shaft to help mitigate these vibrations.

On early engines, the balance shaft sprocket was made of flimsy materials. The M272 sprocket wears down over time, which throws the timing off.

This is a very serious problem that, in most cases, requires the engine to be removed. If timing is thrown out of whack, the M272 may experience complete failure. Metal shavings from the balance shaft sprocket can also wreak havoc.

When the balance shaft fails, a complete loss of the M272 engine is not implausible. Additionally, the cost of properly replacing the balance shaft may exceed the cost of a new engine.

The point is that this is an issue that everyone should be aware of if they are in the market for a Mercedes M272 from 2004 to 2008. Ascertain that this repair was completed previously and correctly. Mercedes addressed this issue with stronger steel balance shaft sprockets on 2009+ M272 engines. While the issue is still possible, it is primarily a problem with earlier models.

Mercedes M272 Balance Shaft Symptoms

Among the symptoms of an M272 balance shaft failure are the following:

  • Check engine light
  • Fault codes
  • Rough running

Generally, a check engine light will illuminate when the sprocket completely fails. This is when timing can become erratic, and appropriate fault codes should be assigned. P0059, P0060, P0064, P0272, P0275, and P0276 are possible balance shaft fault codes for the M272.

Additionally, improper timing results in extremely difficult running. If you notice any of these symptoms, turn off the M272 engine and avoid driving until the problem is resolved. If left unattended, the damage may worsen.

M272 Balance Shaft Replacement

Replacing the M272 balance shaft is a difficult task that should be left to experienced mechanics or do-it-yourselfers. The actual repair kits cost between $400 and $500 in parts. Not bad, but the real issue is the labor.

This job can frequently cost upwards of $2,000 in a repair shop. That is, assuming no further engine damage occurred as a result of the balance shaft failure. Additionally, while the engine is apart for sprocket repairs, you may consider replacing other components.

2) Mercedes M272 Intake Manifold Problems

Mercedes M272 Intake Manifold Problems

Another potentially serious issue is the M272 intake manifold. The intake manifold has a few failure points, most notably the swirl flaps inside the manifold. That will come shortly.

Otherwise, take a look at the M272 manifold’s complicated design and abundance of plastic. The two small black caps are a good place to start. Shafts within the manifold may fail, resulting in the lever breaking and the caps popping off.

Apart from that, components of the swirl flaps may detach and enter the cylinders. This is a less common occurrence, but a very serious one. If the swirl flaps on the M272 manifold travel through the engine, they may damage some internal components.

Once the flaps have made their way through the engine, you will almost certainly require a valve job to repair damaged valves.

M272 Intake Manifold Symptoms

Several of the more common symptoms of M272 intake manifold failures include the following:

  • Check engine light
  • Fault codes
  • Power loss
  • Rough idle

The intake manifold’s function is to distribute air evenly to the cylinders. When components on the M272 begin to fail, airflow may become uneven or insufficient. This can result in check engine lights and fault codes being illuminated. P2004, P2005, and P2006 are three frequently encountered fault codes.

Additionally, you may receive fault codes related to O2 sensors, lean operation, or misfires. Another common symptom is power loss, which occurs when cylinders do not receive adequate air. Finally, the uneven airflow may result in a jerky idle.

M272 Intake Manifold Replacement

When these failures occur, it is usually best to replace the entire M272 manifold. Repair kits are available. They do not, however, address shaft issues on the inside of the manifold.

Certain repair kits do include stronger components to help prevent failure. That is an option, but it is probably best to install the part upgrades on a new manifold to ensure there are no internal issues.

A new intake manifold will cost between $600-700. If you want to include a repair kit to address the external failure points, the price will increase slightly.

The M272 repair is fairly straightforward, and intermediate do-it-yourselfers should have no problem completing the job. Labor costs vary according to model, location, and other factors. However, it is typically about 3-4 hours of labor, so add a few hundred dollars.

3) Mercedes M272 Thermostat Failure

Mercedes M272 Thermostat Failure

All right, we’ll move quickly through the remainder of this post. Engine thermostat problems are almost certainly the most prevalent issue on the M272. In comparison to the previous M272 problems, the map-controlled thermostat is a fairly straightforward failure. These thermostats are electronically controlled to maintain a temperature range of 185 to 221°F for the coolant.

The M272 thermostat may fail to operate properly in either the open or closed position. When closed, it increases the risk of your engine overheating. When the M272 suffers an open failure, it will take an extended period of time to reach operating temperatures. M272 thermostat failures typically occur between 60,000 and 100,000 miles.

M272 Thermostat Symptoms & Replacement

Among the symptoms to watch for are the following:

  • Overheating
  • Engine taking too long to heat up
  • Fault codes

P0597, P0598, and P0599 are frequently used fault codes to indicate M272 thermostat problems. Again, depending on the position of the thermostat, overheating or an inordinately long time to heat up may occur.

Fortunately, the thermostat is inexpensive, costing around $60. Additionally, you’ll require a small amount of coolant to top off the system following the repair. It’s a relatively simple do-it-yourself project that anyone with some basic knowledge and patience should be able to complete. It will take a couple of hours, so those visiting repair shops should budget between $150 and $300 for labor.

4) Mercedes-Benz M272 Oil Leaks

Mercedes-Benz M272 Oil Leaks

Oil leaks are not a common occurrence with the Mercedes M272. Particularly when compared to the preceding M112 V6 engine. However, given the M272’s age, oil leaks can and do occur.

A critical area to inspect is the electrical plugs for the cam adjuster magnets. If oil leaks through the electrical connector, it has a chance of reaching the engine harness. If the wiring harness is damaged, this becomes an expensive repair.

Other relatively common sources of oil leakage include the oil cooler seals and the oil separator. Oil may accumulate on the belt tensioner due to leaks from the engine oil cooler seals. The oil separator’s cover is made of plastic, which degrades with age and mileage and may eventually leak oil.

Oil leak symptoms are fairly straightforward, but here are a few M272 oil leak symptoms:

  • Visible leak
  • Burning oil smells
  • Smoke
  • Low engine oil

Naturally, specific symptoms vary according to the leak’s location. A visible leak is a dead giveaway and is frequently the only symptom present. You may smell burning oil or see smoke if oil drips onto hot parts. A significant oil leak can deplete engine oil more quickly than the normal rate of oil loss.

Mercedes M272 Reliability

How reliable is the M272 engine from Mercedes? In general, the M272 is less reliable than a typical car. While not everything is negative, there are a few serious issues that can result in expensive repair bills or complete engine failure. Fortunately, the balance shaft failures affect only the early 2004–2008 M272 engines.

Though it is improbable, intake manifold problems can also result in serious complications. Thermostat failures may be the most frequently encountered issue on the M272. However, it is a relatively inexpensive and straightforward repair.

Finally, while oil leaks are not common, they are very possible given the age of the majority of Mercedes M272 engines.

Again, just because we’re labeling these issues as common does not mean they’ll affect everyone. Due to the age and mileage of many M272s, they are also prone to a variety of other issues that we did not mention.

Having said that, the M272 is far from a bad engine. The M272 should easily reach 200,000 miles with proper maintenance and repairs. That is not a bad record of longevity.

M272 Common Problems Summary

Mercedes-M272 Benz’s engine is a strong performer for its era and features a naturally aspirated design. However, all engines, including the M272, are prone to common problems.

Keep an eye out for balance shaft gear issues, which primarily affect 2004-2008 models. Balance shaft failure is an expensive repair in and of itself, and it may also result in additional engine damage. On the M272, intake manifolds are another frequent source of failure and repair.

The final two issues are minor, as thermostats are inexpensive to repair and oil leaks are uncommon. However, the M272 is getting older, and many issues become apparent as it ages and accumulates mileage.

While the M272 is not as reliable as a typical engine, it is far from the worst. Ascertain that it has been properly maintained and that common problems have been addressed.

What are your impressions of the M272 engine? Leave a comment and inform us!

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