Low Popping/Knocking noise when driving through rain...

[StimulisRK]

I've had the car for 2 months and it seems like whenever there is moderate to heavy rain, I get a really low popping/knocking sound that I can also feel. It comes from underneath the car, more towards the passenger and back of the car. I haven't driven that much in rain, so idk for sure, but it seems like its mostly when im at higher speeds, then it happens when i accelerate back up (like going 45-60ish then I slow down into 35 then speed back up). And its not like the entire commute I get the popping, just maybe once or twice.

Its really only happened really noticeably like 3 times, but it really freaks me out. The car came with a AEM CAI, and the thought of hydrolock is really starting to scare me... But the one time it happened pretty bad, I stopped and checked under the hood, and the intake head was dry, no wetness at all. And since the noise is underneath the car I'm thinking it has something to do with the exhaust system (all stock btw)

[Pandamanda22]

There is a thread about this somewhere on here but due to my laziness I will try my best to explain. It does not have anything to do with hydrolock though you should be careful with that. You are correct it has to do with your exhaust. It is something that has to do with the rapid compression and decompression of water evaporating on the hot midpipe. That is why the sound is towards the passanger side back of the car. You will be fine. Happens to me every once in a while in the rain.

[mitchlikesbikes]

yeah it's just the exhaust expanding and contracting and vibrating against the bottom of the car. happens to a lot of people