Where is the sunroof drain hole located on a Mercedes-Benz?

[StHaven]

Mercedes-Benz drain holes are found on both sides of the sunroof track, where there are water outlets. Pour water into these outlets on both sides to observe whether the drainage pipes are unobstructed. Solutions for clogged drain holes: Observe whether water flows out from the front fender liner. If clogged, check the cause and remove debris from the sunroof track. Use an air hose to blow out dust from the sunroof opening. Additionally, there are two water outlets covered by rubber plugs in the trunk and the upper part of the door frame. Cleaning methods: The door drain holes can be unclogged with hard objects like iron wires. Be especially careful when cleaning the drain holes hidden in the rubber sealing strips to avoid damaging the seals.

[StMargaret]

My older C-Class had a sunroof leakage issue before. When I took it to the shop for repair, the mechanic specifically showed me the drainage hole locations. There are two small holes hidden beneath the plastic cover of the windshield wipers at the front – you can't see them without removing the cover. There are also two more holes on the inner side of the rear wheel arches where you can feel the rubber tube openings with your fingers. Last time, the rear holes got clogged with leaves, causing water to seep into the trunk and flood the spare tire well. Now, I regularly lift the plastic cover under the windshield and use a bicycle brake cable to clear the holes. Honestly, Mercedes' design is too concealed – you have to crouch by the front of the car with a flashlight to inspect it properly.

[LolaRose]

The basic drainage holes for a sunroof-equipped Mercedes are located at the four corners: one hidden inside each of the plastic decorative panels on the left and right sides of the front windshield, and small holes can be seen by lifting the plastic grille under the wiper arms. There is also a drainage outlet behind each C-pillar, located inside the rear wheel arch. Last week, while helping a friend clean the drainage holes on a GLC, I found the openings were clogged with mud. The professional method is to use an air compressor with a thin tube to blow them out, but a household pump with an IV tube can also work as a substitute. Remember to remove the duckbill valve at the end of the tube before blowing to avoid bursting the connector. It's best to clean them once before the rainy season.

[LaBradley]

Blocked drainage holes can lead to major disasters. My neighbor's E-Class had its front drainage holes clogged, causing rainwater to flow along the A-pillar into the cabin, resulting in over 8,000 yuan in wiring repairs. The specific location is under the plastic panel at the junction of the hood and windshield, where you can feel the rubber hose connector by reaching in. The rear drainage tube outlet is in the frame groove above the rear wheels. It's recommended to check quarterly: pour half a bottle of water into the sunroof and observe if water flows smoothly on the ground behind the front wheels. If the water flow slows or water seeps into the doors, it indicates a need for unclogging. A soft wire the thickness of an ordinary straw can do the trick.

[JudeLee]

Four fixed drainage hole locations: The front drainage holes are at both ends of the lower edge of the windshield, visible after removing the plastic trim panel beneath the wipers. The rear holes are inside the wheel well liners at the corners of the rear doors. When cleaning, start with the front holes—lift the cover plate and use thin steel wire to vertically insert about 30cm from the pipe opening. The rear holes are simpler to handle: lift the side liner of the trunk and directly pinch the rubber outlet to remove accumulated dirt. Regular cleaning is much cheaper than repairs, especially before the rainy season. Note: Do not use high-pressure water guns to flush the holes, as this can damage the sealing rings.

[DeClayton]

Prevention is more important than repair. My experience was that parking under a tree caused the drainage holes to be clogged with fruit pulp. The drainage holes are rubber tubes buried at the four corners of the sunroof track, with exits in the body gaps under the windshield and behind the front wheels. During maintenance, you can ask the technician to check the elasticity of the tubes—aged tubes may collapse. Daily maintenance: Open the sunroof quarterly to clean debris from the tracks; use a plastic straw to suck out accumulated water in the corners; observe whether the drainage outlets under the front windshield are blocked by mud. If there is already a leak, lift the carpet to check if the chassis wiring harness connectors are soaked, and dry them promptly to prevent short circuits.