Flood Damaged Vehicles
No matter how cheaply you can purchase a flood damaged vehicle, it probably won’t be worth it in the long run. We have repaired many flood damaged vehicles. Here in South Florida and coastal areas of Fort Lauderdale, rising water from flash floods are all too common. Salt water flooding is much more damaging than fresh water. Newer Mercedes and other European vehicles are particularly vulnerable to flood damage due to all the state-of-the-art electronic components they have. On top of that, the modern trend is to place these components in low places on the vehicle for better weight distribution for the best handling and dynamics of the vehicle.
Mercedes Benz and BMW chassis have thousands of dollars worth of control units and modules located under the rear seats, only 6 – 8 inches off the ground. If a vehicle is driven into a puddle that is more than 6 inches deep, its possible that water can leak through the body plugs or seals and flood the area under the seats and carpets. Often the owner is unaware of the damage until some electronics malfunction. Meanwhile, the electronics and the electricity flowing through them that are surrounded by water, start to form acid (like inside a battery) that can ruin components, connectors and wires. When the damage is discovered it is usually too late, especially if the damage is discovered due to a musty smell or odor in the vehicle; this would indicate that the moisture (along with the electrolysis) has been there long enough to mildew or form fungus.
If your car is flooded, the key to minimizing the damage is to (1) disconnect the electrical flow through water contaminated circuits. Disconnecting the battery should be the first step. (2) Get the water out and dry up the area as quickly as possible. A wet vacuum can be used to suck up excess water. The carpeting and foam backing on a Mercedes can be up to 4 inches thick. This acts as a sponge and traps the water inside, leading to long term musty smells. At Autobahn Performance we have a portable dehumidifier that can be placed in the vehicle to draw the trapped moisture out of fabrics, carpets and foam under padding.
The next problem to deal with is the electrical connections and components. Any electrical part that is contaminated with water should be disconnected and dried by blasting compressed air through it. The connectors should be cleaned with a solvent and scrubbed with a brush. Components can be cleaned with electrical cleaners. Corroded areas can be cleaned with vinyl bristle brushes and special solvents to remove surface corrosion. Electrical connectors need to be disassembled (pins removed from the connector) and cleaned in solvent. Any connections on components or harnesses that appear to be damaged beyond repair should be replaced. Many electrical connectors and terminals are available from the dealer, but due to their relatively inexpensive cost and difficulty to look up correctly, most dealer parts personnel will try to sell a complete wiring harness. Wiring harnesses can cost upwards of $5000 and can take over 60 hours to install.
At Autobahn Performance, we have access to most dealer parts data bases, so we can look up the wire connectors ourselves. Usually we can repair an expensive or labor intensive harness rather than replacing it. We also have affiliates that can repair some water damaged electrical components, or acquire used components and program them to the vehicle even if they are one time use (previously assigned to a vehicle or VIN).
The most troubling thing about a flood damaged vehicle is that there is usually no way to accurately estimate the cost or extent of the damage. Sometimes after the vehicle is repaired and everything seems to be fine, another problem arises from the same water damage, and still more repairs are needed.
Another common water damage problem is found in the cowl panel (cavity between the engine firewall and the cabin firewall at the base of the windshield) of most Mercedes cars. This is where the climate control system draws in fresh air from the outside. Older vehicles can have corrosion or rust here. This area is almost impossible to repair once it has rusted through. It can be patched but it will leak again within a few years. The replacement panels are available from mercedes but are very difficult to weld in place and usually require removal of the dashboard, engine and other components to install properly. The cowl cavity also has problems from clogged drains.
An incredible amount of water can run off the roof and windshield and collect in this cavity. Debris from leaves that collect on the windshield will restrict the drain to the point that the cavity fills with water and floods components in the cavity and overflows through the fresh air opening of the climate control system into the cabin of the vehicle.
The Mercedes SLK 170 chassis is especially susceptible to this condition. Even minor overflow from restricted drain will cause water to flow across the blower motor, speed regulator, radio amplifier and wire harness connectors. The water is sometimes not discovered for several days and components start to fail; blower motor speeds are erratic or stop altogether, radio stops playing, warning lights appear on the dash, and the vehicle begins to smell musty inside. The carpet and floor insulation system on late model mercedes is made of sponge like foam that is molded to fill all of the irregular cavities under the carpet. The foam is over 6 inches thick in some areas. This foam soaks up and hold water like a sponge.
This SLK was flooded by the customers own lawn sprinkler system. One of the sprinkler heads came loose and the stream of water shot way up in the air and back down on the windshield. The water drains in the cowl at the base of the windshield were slightly clogged with debris and they could not handle the huge volume of water. The water overflowed through the fresh air opening of the AC system and flooded the inside of the vehicle. We had to completely disassemble the interior of the vehicle and replace many of the electronic components; Blower motor and regulator, radio amplifier, Tel-Aid control module / communication module, Radio and the ABS / ETS module (mounted under the hood on the anti-lock brake pump. must also have been electrical short circuit related).