The plastic guide rail, also known as the time guiding chain, is a small rectangular piece of plastic in the engine of Mercedes Benz and some other automobile brands. Its small size makes it look irrelevant, but looks can be deceiving. The plastic guide rail is a vital component in the engine of your vehicle.

If it fails, it might need to be replaced or just fixed. Early diagnosis of a faulty plastic guide rail will go a long way to prevent further damage to your engine. Hence, it is vital to look out for the signs. In this article, we take an in-depth look into the causes and diagnosis of the failed plastic guide rails and the best place to fix them.

Causes of Failed Plastic Guide Rails

People have often asked why guide rails are made from plastic and then put in the hottest part of a vehicle, being the engine? Mercedes and several other vehicle brands use plastic because it has proven to improve the overall performance of the main timing chain. Plastic is also a cheaper alternative to any other raw material. Several factors, with heat as the main factor, can cause the plastic guide rails to fail:

  • Heat: Heat is the most common cause of plastic guide rail failures. Plastic has low thermal conduction; hence, it is very susceptible to the heat generated in engines where it is contained. Overheating of engines or driving in very high temperatures puts your guide rail at risk of failure. So, if your Mercedes has a problem with overheating, you might want to check your guide rails, too, to see if the heat has not strained it.
  • Road bumps: Impact with another vehicle, curb, or pothole can also result in a failed guide rails, especially when bumpy impacts are regular. The plastic guide rails might get worn down, weak, or shatter.
  • Lack of maintenance: Lack of maintenance is a leading cause of failed guide rails. As time goes on, the guide rails of your Mercedes will age and begin to fail. Routine maintenance can help you detect it early and get it fixed. Also, practicing safe driving as a part of vehicle maintenance will also help to prevent major problems from getting out of control.

Diagnosing a Failed Plastic Guide Rail

Prevention is better than cure. Hence, early diagnosis will go a long way to prevent further damage. Below are four common and early signs of a failing plastic guide rail in Mercedes:

  • The engine makes a constant rattling sound.
  • The engine makes grinding noise upon starting.
  • You notice a squealing tensioner.
  • A rough-running engine.

Fixing Failed Plastic Guide Rail

Fixing the plastic guide rails is not an easy task and should be done by professionals. Although the guide rail is inexpensive, installing it will always require a professional. Hence, research the best auto repair shop in your area to fix your plastic guide rails.

Leave it to Our Professionals at Schearer’s Sales and Services

There are lots of Do-It-Yourself videos on how to fix failed plastic guide rails on YouTube. Mercedes Plastic Guide Rail Failure Fix While this might seem like a good enough solution because of the low cost, professional technicians are always the better option. The repair process requires expertise and technical know-how that only trained professionals can offer.

If you are looking for a professional auto repair shop, the solution is Schearer’s Sales and Service. We are here to give your engine that professional touch and maintain your vehicle throughout its lifetime to ensure your safety and pleasure when driving it.

Schearer’s serves clients in and around Allentown, Bethlehem, and Macungie, PA. All our technicians are trained & experienced and have all it takes to maintain and repair your Mercedes. Schearer’s also uses the latest tools and technology to repair and maintain your Mercedes.

For over ten years, Schearer’s has been rated as a top auto repair service center with affordable prices for our customers. Drop by our shop and leave smiling as we handle your vehicle repairs and maintenance quickly and affordably. Call us today or visit our website to book an appointment with us.

* Mercedes Benz Car image credit goes to: Julie Deshaies.

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