Mercedes-Benz M272 and M273 Balance Shaft Problem: How to Check Your Engine by VIN

Last updated: October 28, 2026

In this guide (5 sections)

Mercedes-Benz Balance Shaft Problems and How to Check Your Car
Affected Engine and Chassis Ranges
How to Check Whether Your Engine Is Affected
Mercedes-Benz Balance Shaft Class Action Settlement
Confirm It With Live Data Before You Open the Engine

Mercedes-Benz Balance Shaft Problems and How to Check Your Car

Mercedes-Benz V6 and V8 engines had timing chain problems caused by balance shaft and idler gear failures. Mercedes produced specific models with defective gears in their balance shafts (M272 engines) or with defective idler gears (M273 engines). These faulty gears wear out prematurely and sometimes without warning, causing the vehicle to malfunction, the ‘check engine light’ to remain illuminated, and the engine to misfire, run poorly, or stop running. A lawsuit was filed against Mercedes-Benz; you can read the details below. ¹

Timing chain failures can cause catastrophic engine damage. Early signs of this problem are the check engine light and engine noise. If the timing chain fails, the pistons can hit the valves and cause severe damage to the engine. The M272 was installed in several 280, 300, and 350 models. The M273 was installed in several 450, 500, and 550 models. Confirm the engine designation and full engine number instead of relying on the trunk badge. The repair cost is mainly labor because access requires extensive engine disassembly.

In a few cases, a stretched timing chain can also come from poor maintenance and missed oil changes. These engines had problems because weak materials were used for the balance shaft sprockets and the timing chain idler gear. The materials were updated later in production. You can find out whether your engine has the weak parts from its engine serial number, and the steps below show how to get that number from your VIN. Before opening the engine, read the stored codes and camshaft adaptation values with a full system scanner to confirm the symptoms match.

Affected Engine and Chassis Ranges

Early M272 and M273 engines, model years 2004 to 2008.

Applications:

2004 to 2008 SLK350
2004 to 2008 CLS350
2005 to 2008 CLK350
2005 to 2008 C350
2005 to 2008 E350
2005 to 2008 S350
2005 to 2008 SL350
2006 to 2008 R350
2006 to 2008 ML350
2006 to 2008 Sprinter
2004 to 2008 SLK280
2005 to 2008 CLS280
2005 to 2008 CLK280
2005 to 2008 C280
2005 to 2008 E280
2005 to 2008 SL280
2006 to 2008 R280
2007 to 2008 S280
and more.

Chassis codes covered by the Mercedes-Benz bulletin:

ML-Class: 164.156/172/186/871/886
SLK-Class: 171.454/456
C-Class: 203.052/054/056/087/092 and 204.054/056/081/987
CLK-Class: 209.356/372/456/472
E-Class: 211.056/072/087/090/256/287
CL-Class: 216.371/386
CLS-Class: 219.372
S-Class: 221.171/186
SL-Class: 230.471
R-Class: 251.156/165

The bulletin’s balance shaft and idler gear scenario does not apply to 164.156, the 204 C-Class or 216.386.

Problem 1: Balance Shaft Sprocket or Timing Chain Idler Gear Wear

This repair requires extensive labor. Consult the chassis specific WIS procedure to determine whether engine removal is required.

Problem 2: Camshaft Adjustment Solenoids

The camshaft adjustment solenoids at the front of the cylinder heads can fail or leak oil and need to be replaced.

How to Check Whether Your Engine Is Affected

Step 1: Get Your Engine Serial Number

Go to this page and use one of the options there. You will be taken to an external site where you can check the engine and transmission serial numbers. Enter the VIN, select Search, and look for your engine serial number.

You can also get your engine serial number by calling your MB dealer. The serial number will look something like this.

check c s r ml clk 350 engine problem — Example: How to check your MB for balance shaft problem by VIN and Engine Serial Number.

Engines produced after these cutoff numbers received revised components:

M272 Engine Serial No. 2729..30 468993
M273 Engine Serial No. 2739..30 088611

Step 2: Read the Fault Codes

If your engine serial number is lower than the serial numbers shown above, scan the engine ECU, which is very easy. A basic OBD-II code reader costs less than $20, and any of these Best Selling OBD-II Scanners and Code Readers on Amazon will read the generic codes. The UCAN-II Pro full system scanner also reads the Mercedes-specific codes below and the other systems in your Mercedes-Benz, and has coding functions that cheaper readers lack. Plug the scanner into the OBD-II port under the dashboard and read the fault codes from the engine ECU. You will get fault codes if your check engine light is on. If it is off, you could still find pending codes, which means the engine has detected the problem but has not yet turned on the check engine light.

Hopefully, you don’t have any of these codes:

Mercedes fault code 1200 or 1208, pending or stored, that comes straight back after you clear the fault memory. A generic OBD-II reader shows these as P0016 or P0017. On engines below the cutoff, this points to a worn balance shaft sprocket (M272) or timing chain idler gear (M273).

Mercedes fault codes 0059, 0060, 0063, 0064, 0271, 0272, 0275, and 0276, recorded as current or pending in the ECU fault memory, are caused by a malfunctioning camshaft adjustment solenoid. If you have these codes, check for an oil leak at the camshaft adjustment solenoids. The bulletin lists improved solenoids from M272 2729..30 759427 and M273 2739..30 193592 onward.

Step 3: Inspect the Gears

If your engine serial number is within the affected range, you may want to inspect further. Remove the timing case cover and check the teeth on the balance shaft sprocket (M272) or the timing chain idler gear (M273) for wear. If you confirm the balance shaft problem, the repair is very labor intensive, and on many models the engine has to come out. Our M272 balance shaft and timing chain repair guide covers the job.

Mercedes-Benz Balance Shaft Class Action Settlement

There was a lawsuit against Mercedes-Benz USA LLC where the plaintiffs alleged that Mercedes produced certain vehicles with defective gears in their balance shaft for the M272 and defective idler gears in M273 engines.

Case Name:
Majeed Seifi, et al. v. Mercedes-Benz USA LLC
Case No. 3:12-cv-05493
U.S. District Court for the Northern District of California.

Historical Settlement Status: The Court granted the Motion for Final Approval, approved the Settlement, and certified a Settlement Class on August 17, 2015. The Settlement Effective Date is October 20, 2015. Decisions on timely claims were due by January 18, 2016, and checks for valid claims by February 17, 2016. Those deadlines have passed, so the settlement no longer accepts claims.

Lawsuit Details

There are two specific ways to receive compensation from this class action settlement. Extended guarantee: Mercedes has agreed to cover qualified future repairs up to 10 years or 125,000 miles to the sprocket of the balance shaft gear in M272 engines or the idle gear in M273 engines. Percentage based reimbursement: Mercedes will pay a percentage of the costs for repairs associated with this defect as follows: Repairs not done at an authorized Mercedes dealer will receive a reimbursement up to $4,000. If the repair took place between 4 years or 50,000 miles and eight years or 80,000 miles, Class Members would receive 70 percent of those costs. If the repair occurred between 8 years or 80,000 miles and ten years or 125,000 miles, 37.5 percent of the costs would be reimbursed. No reimbursement will be sent to Class Members who have repaired vehicles after the vehicle was ten years old or had 125,000 miles on it. Repairs must have been done before May 13, 2015.

Court docket: Seifi et al. v. Mercedes-Benz USA, LLC

Balance Shaft TSB Issued by Mercedes-Benz (bulletin S-B-03.30/08i, April 2009)

Confirm It With Live Data Before You Open the Engine

The generic P0016 and P0017 codes also come from a failed camshaft sensor or solenoid, so a code alone is not proof of a worn sprocket. Clear the codes and see whether 1200 or 1208 returns straight away, as the bulletin describes, and compare the camshaft position values in live data with the specification before you commit to an engine-out repair. The UCAN-II Pro reads the Mercedes engine codes and the camshaft live data on these engines. If the codes point at a camshaft sensor rather than the gears, see our camshaft position sensor guide.

References

Seifi, et al. v. Mercedes-Benz USA, LLC website

Next step

Run a full system scan on your Mercedes-Benz

Before you buy parts, scan every control module, not just the engine. It shows the root fault behind the warning lights and tells you whether the problem is still active. See how to do a full health check.

MB Medic Mercedes-Benz Repair Guides, Service, How To DIY