Chevrolet Malibu trunk water leak issue with spare wheel compartment filled with water on Chevrolet Malibu

Some Chevrolet Malibu owners report experiencing water leaks in the trunk, often resulting in the spare wheel compartment filling with water. These leaks may occur due to water entering through pressure valves located in the rear quarter panels, leading to accumulation in the spare tire well. A common issue is the rear compartment lid weatherstrip not being properly seated, which can allow water to seep in around the trunk opening and deck lid hinges. Additionally, misapplied trunk body sealant at the left tail lamp pocket may create a leak path. Technical Service Bulletin (TSB) #09-08-57-004B from GM provides guidance for technicians on identifying and resealing leaks in the trunk area. Some owners also notice vertical "snail trails" of water behind the plastic trim on the aft bulkhead, indicating potential pooling along panel sealant lines and drain plugs. To address these concerns, it is advisable to inspect the pressure valves, ensure the weatherstrip is seated correctly, check the trunk sealant, and refer to the TSB for detailed repair instructions.