Last night there was a huge thunderstorm. During a massive downpour where I could barely see out of my window, I ended up driving onto a flooded street, by the time I realized how deep the water was I was already halfway through it. It felt like my care was a little sluggish, but I don't know if that was an issue with the actual engine performance or pushing through all that water. It never died and after getting to the other side performed like normal besides some wet brakes. I was only about two miles from home and was able to make it home without a problem. Today the car starts up fine and runs as normal, but I wanted to at least go get the oil changed.

Afterwards, I went to change the air filter and noticed there is some standing water at the bottom of the air intake box where all the debris is usually sitting and my air filter was wet.

I have no noticeable performance issues, no error codes, but am worried there may be permanent damage and would like any advice as to what to do next? Should I get the transmission fluid changed?

It is a 98 Cavalier and I really need this car to last me another 2 or 3 years. Any advice is appreciated.


  • 2
    Consider yourself lucky. If there was water at the air intake box, and the air filter was wet, you were near a hydrolock occurring. Hydrolock is when the water enters the engine, and being incompressible, destroys it.
    – juhist
    Feb 25, 2018 at 19:26
  • @juhist Hydrolock requires a significant intake of water though, so the water would have to tear through the air filter, most cars will die from air starvation before taking on enough water. It's people trying to restart the car and sucking in more and more water that I have seen destroy most engines. Feb 28, 2018 at 17:58

2 Answers 2


The first thing will be to replace the air filter, after that yes, you can get the transmission fluid checked - it is most likely ok...

As you have since driven the vehicle then the brakes should be working fine otherwise you would have noticed.

Keep an eye on it but it sounds like you were lucky.

A similar question here with a longer answer.. The effect of hitting deep water hard


Based on a family member driving our car into a lake:

  • Change the air filter as that is cheap and now soaked with tons of dust and crap.
  • Check all of your fluids, although the brake fluid and power steering reservoirs are pretty high up and safe, if you have a leak, they could not contain a significant amount of dirty water, they may be due for changing anyways. Engine and transmission oil have a lower entry point because of the dipstick and dipstick tubes, so you want to check them for water, if none exists, you are good but if you are due for a service interval, you're not doing yourself any harm changing it.
  • Check that all electrical stuff that is encased (like the under the hood fuse box) is dry. If it is wet, disconnect the battery, remove fuses and dry the area. Repeat for any other areas like a relay box, etc.
  • Afterwards, I would recommend going to a self wash and using a "low-pressure spot-free" rinse to wash any other crap away. It's not needed but may help you identify areas that take on water and should be checked. It's not water that causes electrical problems anyways, it's dirty water and the corrosion and unintentional electrical connections it can cause.
  • If no water got into the vehicle, then you can stop there. IF water got into the vehicle, your main concern is checking the fuse box for water and drying the area so it doesn't corrode and lead to electrical issues.
  • Also do yourself a favor and dry out the carpet ASAP or you will have mold and stinky smells.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .