How to Deal with Water Leakage in BMW 3 Series Trunk?
2 Answers
First, you need to identify and block the source of the water leakage to determine where the water is coming from and how it is entering the trunk. If this step is skipped and you only focus on draining the water, the source of the leak will not be controlled. At the bottom of the trunk, where the spare tire is located, there are drainage holes designed to allow any water inside the trunk to drain out through these holes.
In my car enthusiast group, trunk water leakage is a frequently discussed issue. For the BMW 3 Series, common causes include aging sealing strips or clogged drainage holes. Last week, I witnessed my neighbor dealing with his 318i - when he used a high-pressure air gun to clear the drainage holes, a lot of leaf debris and mud came spraying out. If the edges of the rubber seals become hardened and cracked, the entire set needs replacement. Never try to save money by just applying silicone sealant, as water will still seep through during heavy rain. The corner of the spare tire well in the trunk is most prone to water accumulation. If water ingress is found, immediately remove the interior trim panels and thoroughly dry the area with absorbent cloths, otherwise rusting of electrical connectors may lead to electronic malfunctions. After treatment, it's recommended to conduct a water spray test - use a flashlight to inspect water flow traces under the vehicle to accurately locate the leakage point for a permanent solution.
