Though it may seem like a simple enough piece, the timing chain guide, a small rectangular piece of plastic in your car’s engine, is a critical component that can tell you a lot about the health of your engine. The main function of the timing chain is to make sure that the rotation of the camshaft and the crankshaft is synchronized. The primary function of the timing chain guide is to keep that chain on its track and avoid any misfiring in the engine.

The chain guide in your Mercedes Benz is plastic, as are the chain guides in most vehicles. Since all internal combustion engines operate at high temperatures, the plastic chain guide, with its location in the heart of the engine, is prone to wear over time. In addition to supporting the timing chain, the guide can clue you into the condition of other areas of your vehicle. Erratic wear patterns on the guide could indicate an issue with the timing chain, and the softer material of the guide is sensitive to highly acidic liquids, such as oil that has not been changed frequently enough. Most importantly though, it is needed to keep the timing chain moving in a tight circular motion in order to ensure proper timing and combustion.

Why would Mercedes-Benz make such a critical component out of plastic when it is located in such a volatile environment within the engine? Well, it’s standard for most vehicles to use plastic as it’s been found to improve the performance of the actual timing chain, and in addition it reduces manufacturing costs. So it is likely you will need to look into replacing this particular part at some point.

Repairing a Guide Rail

Though the part only costs around $15 to buy, replacing it entails a bit of know how and labor. Before investing your time and money into replacing this item yourself, make sure you consider the following:

Ability to Diagnose the Problem

Early warning signs of a problem with your timing chain guide include:

• Rattling or clicking sound from the engine
• Grinding sound upon starting engine
• Squealing tensioner
• Generally rough running engine

These signs are similar to many issues related to the timing chain as well as other problems in the engine so further investigation into the engine would be required to pinpoint the problem.

Accessing the Guide Rail

This part, though prone to wear, is not often checked during regular maintenance due to the fact that it requires a lot of labor to take apart the engine enough to reach it. Before attempting to further your diagnostic check of this part you will want to consider that you may spend several hours taking apart the engine and that the repair itself, though a simple part, is connected to a very complicated system in your engine.

Checking for Issues Caused By the Broken Chain Guide

The guide rail is so important to supporting the timing chain that if it breaks or wears unevenly it could create a domino effect in your engine. You need to be prepared to check for the following issues:

• Loose timing chain: If your timing chain is loose it could lead to your engine backfiring or total power loss.
• Uneven wear to the parts surrounding the timing chain: The timing chain could shed metal shavings or rub against other parts in the engine that it should not be if it’s fallen off of its guide. This leads to accelerated wear and potentially devastating problems if pieces of metal are lodged in other moving parts of the engine which could mean more issues and repairs down the road.
• Plastic pieces from the broken guide: If the plastic guide rail broke into pieces, these could cause issues as they make their way into your oil pan, leading to clogs and polluting your oil.

Leave it to the Professionals

While it may be tempting to try to fix on your own, there are risks to making this particular repair without the proper guidance and expertise. Our team at Das European Autohaus in Spring and Houston, TX has the expertise to help you decide how to maintain or repair your Mercedes Benz.

Das European Autohaus only hires repair technicians experienced in European auto care, which means they know the specific idiosyncrasies of your vehicle. They have the knowledge, experience and equipment necessary to help you make an informed decision about the care and maintenance of your Mercedes Benz.

* Mercedes-Benz C-Class image credit goes to: teddyleung.