How to Check for Water Damage in a Car

car submerged in waer

When you are looking for a used vehicle, it is wise to stay away from vehicles that have had water damage. Water is an enemy of cars in many ways, causing damage such as:

  • Electrical problems
  • Engine damage
  • Mold and mildew that is difficult to remove
  • Premature corrosion and rust
  • Seizing mechanical parts like wheel bearings

When a vehicle has been in a flood, it is usually declared a total loss by its insurance company. That’s because flooded vehicles are expensive to repair - water damage can dramatically affect a vehicle’s life expectancy and reliability. Given a choice, a buyer should always choose a vehicle that hasn’t experienced water damage.

It’s possible when you are looking at a used car that you haven’t been informed by the seller that the vehicle was water damaged. It may be because:

  • The seller is not the original owner and doesn’t know about it themselves
  • The seller is hiding that they are aware of water damage
  • The vehicle wasn’t insured and the water damage wasn’t disclosed after repairs

Whatever the case, you can check several things to help you determine if a vehicle has water damage before you buy it.

Method 1 of 5: Perform a VIN check

Obtain a detailed vehicle history report from a reputable source to check for any title issues relating to water damage.

vin number check

Step 1: Find the VIN. Obtain the vehicle’s Vehicle Identification Number, or VIN.

The VIN number is a unique 17-digit number that is assigned specifically to each vehicle.

It is located on the driver’s side dashboard, visible through the windshield.

vin in driver side door jamb

You can also find it on the driver’s door pillar, and on many other body panels.

Another place to look for your VIN is on the car’s title and registration documentation.

Step 2: Find a reputable vehicle history report website. CARFAX, CarProof, and AutoCheck are great websites for checking your VIN.

Step 3: Pay for the report. An individual vehicle history report can vary slightly in price, depending on which site you select.

Enter your credit card information, or you may be able to use PayPal in some cases.

Step 4: Read through the VIN check report.

vin report showing salvaged vehicle * Look for instances of water-related damage, the term “flood,” or a title status that refers to “salvage,” “rebuilt,” or “total loss.”

If the VIN report doesn’t show any reference to water damage, it’s unlikely the vehicle was involved in extensive water damage.

  • Warning: If a vehicle was not insured when it experienced water damage or flooding, it may have been repaired by the owner without the title being affected at all. A VIN report may not catch every instance of water damage but is generally quite helpful in weeding out water-damaged vehicles.

Method 2 of 5: Check for premature corrosion

Vehicles that have been submerged or water damaged will typically have more corrosion, or corrosion in atypical places, compared to vehicles in normal conditions.

car wire corrosion

Step 1: Inspect the electrical components for corrosion. Corrosion on electrical components usually presents itself as white, green, or bluish fuzz on connectors and electrical parts.

Step 2: Check for corrosion in other parts of the car. Look at the fuse block under the hood, major electrical connectors, chassis ground cables, and computer modules.

  • Tip: Corrosion on the battery terminals is not a good indicator of water damage. This type of corrosion and buildup can develop under normal conditions.

If there is corrosion on electrical components, it’s possible the car was involved in water damage.

Minor corrosion may develop over time, so consider the vehicle’s age when determining if the corrosion is excessive.

image showing rust inside of the door jamb

Step 3: Check for sheet metal rust. Interior parts that are rusty are telltale signs of water damage.

Step 4: Check less obvious spots. Look at the underside of the hood, the trunk lid, in the spare tire well, and under the seats for rusting metal parts.

Method 3 of 5: Check for electrical issues

Water and electricity don’t mix, so if a car has experienced water damage there will usually be electrical repairs required. Some electrical problems don’t manifest until later or the issues can be intermittent.

Step 1: Check each electrical system’s operation. When you are looking at a used car for sale, make sure the system is operational by turning it on and off multiple times.

car lights one on one off

Step 2: Check the lights. Turn on each light including the turn signals, headlights, brake lights, reverse lights, and interior lights to make sure they work.

It’s possible for a bulb to be burnt out but if the a system doesn’t operate, there may be a water damage situation.

For example, if the left turn signal illuminates but doesn’t flash when it is turned on, there could be an issue related to water.

car instrument cluster with indicator lights on

Step 3: Examine the instrument cluster for problems. If there are malfunction indicators lit such as the engine light or ABS light, there may be an issue.

Step 4: Check the power controls. Roll down each power window and check that each power door lock works as it should.

Step 5: Diagnose any problems. If electrical problems come up, have the seller get them diagnosed before you complete the purchase.

They may or may not be water-related but you’ll at least have an idea of what repairs are required.

  • Warning: If the seller is unwilling to have problems looked at, they may be trying to cover up a known problem.

Method 4 of 5: Check the upholstery for water staining

car upholstery showing water stains

Step 1: Check the seats. Look very carefully at the seats for abnormal water stains.

A small water ring is typically just a spill but extensive water stains may be a larger issue.

Water staining on multiple seats can indicate abnormal water damage.

car showing water lines

Step 2: Look for water lines. Look for lines or stains on the door panels.

The fabric on the door panel may swell, indicating a water line.Look for similar damage on multiple panels to be sure of water damage.

Step 3: Check the carpets. Look at the carpet in the car for water exposure.

It’s normal for water or snow to get on the carpets in small amounts, but if there are water stains higher up in the footwells, under the seats, or on the carpeted sills near the doors, there may have been water damage.

There may be silt or dirt from the water still in the carpets as well.

Step 4: Check the headliner. In extreme cases where the car was submerged, the headliner can get wet.

Check for swelling around the edges of the headliner or around the dome light.

fabric drooping from headliner

Look for the fabric separating and drooping from the foam on the headliner.

Method 5 of 5: Check the car’s mechanical operation

person holding cap with milky fluid on it

Step 1: Check all the fluid conditions. If there was water in the engine, transmission, or differentials, it can turn the oil a milky color and consistency.

Step 2: Perform a test drive. If the engine is running rough or the transmission isn’t shifting well, there may have been water in them at some point. While it's not necessarily water damage that's causing this, it's always best to get engine or transmission issues diagnosed before purchasing.

Set the cruise control when you test drive the car.

Listen for abnormal operating noises.

A squeal or grinding noise from the brakes may be nothing to worry about but when combined with other symptoms it can reinforce a suspicion of water damage.

As you work your way through these steps pay close attention to anything unusual or out of the ordinary. If you find anything else amiss with the car you’re checking for water damage be sure to make a note of it so you can factor it into your buying decisions. If you prefer to have a professional check over a potential purchase, contact one of YourMechanic’s certified mechanics to complete a pre-purchase inspection to thoroughly check the car you’re interested in.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

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