There are few vehicles in the past decades as dynamic and innovative as the Mercedes car family. For years, Mercedes has been at the forefront in finding new ways to improve your everyday ride. These models are expertly designed and crafted for your enjoyment, comfort, and safety. Even cars with the best human engineering are prone to problems and issues with enough age and use. The Mercedes plastic guide rail is an example of a part prone to failure.
The guide rail is a crucial part of ensuring that the engine on your Mercedes is running correctly. It works alongside the engine’s timing chain and helps it circulate and function properly alongside the rest of the engine components. The guide rail works similarly to a cast or bone splint in that it prevents the timing chain from becoming misaligned or falling out of place.
The primary way to detect if the plastic guide rail is failing in your Mercedes is that your car will shake and vibrate when the engine is running. The guide rail loosens and starts to bang against the other parts of the engine under the hood. Therefore, the easiest way to know if your guide rail is failing is simply to listen to the noises your car is making.
Causes of a Guide Rail Failure
Several things can cause guide rail failure in your Mercedes. If you notice one of these warning signs, bring your Mercedes in right away:
- Excessive Heat: Heat is the number one cause of guide rail failure. Excessive heat from the engine will melt and bend the plastic guide rail and eventually cause it to become brittle and break down. If you see your engine temperature gauge rising, bring it in immediately.
- Prolonged Impacts and Bumps: Constant bumps and severe road impacts can lead to straining and loosening of the plastic guide rail. If you must drive on bumpy roads that have potholes, debris, and bumps, take these cautiously.
- Age and Maintenance: Even the Mercedes is not immune to the wear and tear of age and lack of regular vehicle maintenance. If you get your vehicle serviced and maintained regularly, it will increase the lifespan of your guide rail.
- Constant High Speeds: Driving at high speeds for long periods of time can cause guide rail failure due to the excessive engine heat. This will lead to melting, bending, and brittleness and even cause the timing belt to lock up completely. Routine maintenance to ensure your cooling system is working properly can help ensure this does not become a problem.
What Happens When Your Guide Rail Fails in Mercedes
The guide rail itself is not an extremely expensive part. The big issue is what happens to the rest of the pieces around the guide rail when it begins to fail. Due to the excessive vibrating of the guide rail as it loosens, it begins to break apart, and pieces will end up falling into the oil pan. This can cause clogs as the oil attempts to circulate throughout the engine. This debris can lead to significant engine damage.
If this debris doesn’t cause the engine to break down, then the complete failure of the guide rail certainly will. As it continues to break down, the guide rail will break into progressively smaller pieces until it eventually shatters completely like a grenade with shrapnel. The resulting shards will break off and puncture the engine components around it, immediately causing total engine failure. This is the worst-case scenario of guide rail failure but is a definite possibility.
If you suspect your Mercedes has a guide rail issue, it is a good idea to get this problem checked out by our professionals as soon as possible.
Get Help From a Professional Who Cares
As with all vehicle issues, you should seek immediate service from a professional mechanic. 
If you are in the Louisville, KY area, then Turning Wrenches is the place for you.
Turning Wrenches is Louisville’s Mercedes service and repair experts. We are happy to assist you with all your vehicle needs. Since 2013, we have been providing quality and specialized Mercedes auto services. Turning Wrenches implements the best diagnostic tools on the market to ensure that we take care of every problem you may encounter, including guide rail issues.
Call today or visit us online to schedule your appointment. We commit to making your Mercedes repair experience a convenient one!
* Mercedes Benz Car image credit goes to: Julie Deshaies.