What to Check After Driving Through Water

Essential Post-Flood Checklist: What to Inspect After Driving Through Water

Driving through water, whether due to heavy rain, flooded roads, or unexpected puddles, can pose a significant risk to your vehicle. Water can damage essential components, leading to costly repairs or even rendering your vehicle unsafe to drive. After encountering water on the road, it’s crucial to conduct a thorough inspection of your vehicle before you start it or drive it to ensure it remains in good working order. This article outlines the key areas you should inspect to protect your vehicle and prevent potential damage.

Check the air filter after driving through water

Most cars and trucks made in the 90s and later have cold air intake systems that draw air from low areas behind the front grille. When you drive through high water, the cold air intake can suck water up into the air filter box. If it sucks in enough water, it can cause the paper air filter to disintegrate, allowing water into the combustion chambers. Since water doesn’t compress, it can “hydrolock” your engine, damage pistons, and break valves.

That’s why it’s so important not to try starting the engine until you’ve checked the air filter.

1) Check the air filter

Is it wet?

If yes, then it sucked in water (skip down to “If the air filter is wet”).

If it’s not wet and there’s no water inside the air filter box, then your engine isn’t at risk for hydrolcok.

If the air filter is wet

Check for signs of water in the air duct between the air filter box and the throttle body. If you find evidence of water, there’s a good chance it got into the engine. Do NOT TRY AND START YOUR ENGINE. Call a tow truck and have it checked out by a shop.

So you should immediately check these items before pro

2) Check for water inside the cabin

If you drove through water that was high enough to enter the cabin and soak your carpet, chances are you’re going to have electrical problems. Do NOT start the vehicle. Have it towed to a shop.

The shop should check the following items after driving through water:

• Water in the starter
• Water in the differential and transmission
• Water in the alternator, fuse box, wiring harness
• Full battery and charging system test.
• Damage to engine splash guards

If all that checks out, the shop should test drive the vehicle to check engine, transmission, and braking operation.

3) How to deal with a wet interior

The water inside the cabin can cause serious electrical and mold issues. Flood water contains all kinds of contaminants like oil, acids, and salt that can damage circuit boards, motors, and wiring. If you have water in the cabin, you must treat this as a flooded vehicle. For step-by-step instructions on how to deal with a flooded vehicle, see this article

In almost all cases of water intrusion into the cabin, you’ll have to remove the seats, carpet, and padding to dry out the interior. A vacuum will not get the water out of the padding!

4) Inspect the Transmission Fluid

Water can also infiltrate the transmission through the breather vent, leading to significant issues if not addressed promptly. After driving through water, check the transmission fluid for any signs of contamination. Like engine oil, contaminated transmission fluid may appear milky or cloudy. If you notice any irregularities, it’s essential to have the transmission fluid flushed and replaced as soon as possible to prevent damage to the transmission components.

5) Inspect low-mounted components

Driving through water can flood low-mounted components like the alternator, starter, and A.I.R secondary air pump. If they get wet, don’t start the engine. Remove the components and dry them out with compressed air. In the case of the A.I.R. system, compressed air is used to blow out the hoses and dry the pump and solenoid switching valve.

©, 2023 Rick Muscoplat