Mercedes-Benz is one of the most reliable and competitive producers of exceptionally durable and long-lasting vehicles on the market. However, one common issue that arises for many Mercedes drivers is the failure of the balance shaft. The balance shaft gear is responsible for helping to balance out engine components and prevent harmful vibrations at high speeds and when shifting gears. It does this by acting as a counterweight to these engine components as the vehicle accelerates, keeping them as still and secure as possible. Failure of this gear could mean significant damage to your vehicle’s engine. Let’s discuss how to recognize this failure in your Mercedes.
Common Warning Signs of Balance Shaft Failure
Balance shaft failure is a common issue in Mercedes models equipped with the V6 piston engine, mainly the Mercedes M272, manufactured in 2004 to 2008. Symptoms of a balance shaft failure are as follows:
- Rough idling and/or running: When stopped at a red light or driving at speeds that wouldn’t normally be an issue, your vehicle may no longer sit still or drive smoothly, but instead have a strong rumble, both physically and audibly.
- Engine stalling or misfiring: Your vehicle may suddenly stall while driving or may have trouble starting up.
- Loud rattling or vibrating noises from the engine.
- The check engine light is turned on.
Balance shaft problems can not be ignored or put off. Failure of the balance shaft leaves the inner components of your engine unsecured and therefore will ultimately result in damage to the engine if left unchecked. Driving at high speeds for long periods can agitate the problem even further due to the constant vibrations without a proper securing mechanism. If you are noticing any of the above symptoms, contact your trusted local mechanic at Mark Douglas Motorworks to schedule maintenance as soon as possible.
Can balance shaft failures in a Mercedes be avoided?
This gear is intended to last up to 50,000 miles before needing to be examined. Because the only real cause of failure is wear and tear over time, treating your vehicle well by not abruptly switching gears or allowing overheating is the extent of what you can do to avoid this problem.
This is emphasized by the fact that Mercedes suffered the fate of several class action lawsuits due to this defective gear and the defective timing chains in M273 engines. They consequently offered an extended warranty and reimbursements based on mileage and time of repair.
It is theorized that there was a significant flaw in the production of this product. It may not have been hardened properly during the manufacturing process. This resulted in the gear wearing down a lot faster than expected and failing to function properly within as little as a year.
Although there is not much to be said about how to stop the failure of this gear, keeping up with regular maintenance and having your mechanic thoroughly check the engine all components will help to catch the issue before it becomes dangerous or damaging in any way.
How to Fix a Faulty Balance Shaft Gear
The only solution to this problem is to have the balance shaft gear replaced. Because of the high price, $4000 and higher, many people who have had to deal with this issue are tempted to put off such an expensive repair.
We recommend that you avoid any delays to repair upon observation of any of the above symptoms. Putting off maintenance of such an issue for too long will almost certainly lead to further, more permanent damage to your engine. It may even lead to the need to have the entire engine replaced, ultimately costing you far more money than a repair bill.
Schedule a Repair With an MDM Expert Right Away
Our highly-qualified mechanics at Mark Douglas Motorworks provide services to 
all makes and models, Mercedes Benz being one of our specialties. Both the performance of your vehicle and your safety are important to us, and with our expertise, you can rest assured that you are in good hands.
As soon as you notice any of the listed symptoms, or if your check engine light has come on, call your local experts at Mark Douglas Motorworks in the Orange County area, including Mission Viejo, Lake Forest, Costa Mesa, Irvine, Huntington Beach, Laguna Hills, and Laguna Nigel, CA.