2009 Mercedes C300 Belt Diagram (2024)

FAQs

How do you find the serpentine belt diagram? ›

Some vehicles have the serpentine belt diagram located on a decal somewhere in the engine compartment. But if your car does not have a decal, you can easily look up the diagram in a repair manual or repair database. Another option is to take a photo of the old belt before removal.

Labor costs are estimated between $94 and $118 while parts are priced between $29 and $42. This range does not include taxes and fees, and does not factor in your unique location.

A: Commonly a belt routing diagram sticker is on the underside of the hood or in the engine compartment. If there is no diagram, make a sketch of the belt and pulleys before removing the belt. This will help you re-route the new belt correctly.

Pinch that point between your index finger and thumb and move it back and forth. The belt should have about a half an inch of play when at the appropriate tightness. If there is less than a half an inch, the belt will need to be loosened, if there is more, it will need to be tightened.

You can replace only the pulley, or you can buy a new tensioner with a new pulley attached, or you can buy a kit with a new belt, tensioner/pulley, and idler pulley if there is one, and do it all.

Replacing the serpentine belt is as simple as threading it into position, cranking the tensioner and slipping the belt over the tensioner pulley, or nearest pulley up top. Belt tensioners are mostly spring tension. Once installed, the spring retains pressure to the belt.

That is why it's so important to stay ahead on your car service and get your belt replaced before it completely breaks. Depending on your vehicle, and the other service you may or may not be having done at the time, the whole process of replacing the serpentine belt should take no more than two hours.

Your timing belt should be replaced anywhere from 40,000 to 60,000 miles and your serpentine belt should be replaced anywhere from 30,000 to 60,000 miles. We recommend consulting your owner's manual for Mercedes-Benz year, model, and trim specifications.

A timing belt has horizontal “teeth” designed to fit the cogwheels of the crankshaft and camshaft. A serpentine belt has V-shaped grooves that run vertically along the belt.

Check if the belt runs centrally on the pulleys. Any sideward movement or slippage can indicate misalignment. Straightedge or String Line: Place a straightedge or taut string along the faces of the pulleys to see if they line up perfectly. Any deviation from a straight line suggests angular or parallel misalignment.

What happens if you over tighten serpentine belt? ›

Excessive Wear: A serpentine belt that is too tight can cause excessive wear on the belt and other components, leading to premature failure. The added tension can cause the rubber on the belt to wear down more quickly, which can cause the belt to crack or break.

Misalignment pulleys or tensioner: If the belt is not properly aligned on the pulleys, it can wear unevenly or slip off entirely, leading to its premature failure. This situation usually happens if some of the components have been previously removed, replaced, and not returned in to place properly.

You can find the correct size of serpentine belt for your car in the owner's manual or by using an online belt sizing tool. If you are unsure about the size of the serpentine belt you need, it is best to consult a mechanic or an auto parts store.

The serpentine routing is mainly used to compensate the parts with less delay in the "same group of related" signal lines.

Check if the belt runs centrally on the pulleys. Any sideward movement or slippage can indicate misalignment. Straightedge or String Line: Place a straightedge or taut string along the faces of the pulleys to see if they line up perfectly. Any deviation from a straight line suggests angular or parallel misalignment.

Turn off the engine and remove the serpentine belt. Shake and spin each pulley to check if there is excessive play or noise. Any play or back-and-forth movement indicates a bad pulley bearing.