Every time I drive in hard rain I hear this weird noise from the engine, the more water on the road the worse the noise get. I've been trying to find out what can cause that but no luck so far.
The noise is similar to grinding metal! So it's very annoying and kind of scary too. As soon as the road starts drying out the noise is gone!
Did anyone ever had a problem like that?

 

Must be water spraying against something.

Did you take your undertray off? partially off?

 

That was my first guess, but I can definatelly hear the noise coming from the engine or drive train. When I push open the throtle the noise gets louder as rpm rise. It seems like there's water in the turbo!

 

Oh trust me you'd have bigger problems if water was going through your turbo to make that kind of noise.

Likely its like a fan being hit with water or something simliar. Maybe a plastic piece dragging on the ground.

 

i hear all kinds of noises coming from under the car in the rain...but i dont have an undertray on, so that might have something to do with it

 

Do you have the stock exhaust on the car?

My car used to do this as well. It was a combination of things with my exhaust. I think the exhaust would stay hot on the side closest to the chassis but the underside would cool down and contract thanks to the rain. This would basically put a huge bow in my exhaust and make it hit the chassis. This was the loudest and most frightening noise. A little "massaging" for clearance and the problem was gone.

I think the other issue is just a change in the harmonics of the pipe with the water beating on it. I haven't been able to do anything about that. It does sound noticeably different in the wet vs. the dry though and is a little unsettling.

 

Does it still do it if you put it in neutral and coast for a while?

If it still makes noise, then it may be your tires. I have had some tires in the past that are really loud in the rain, but quiet on a dry road.

 

I put a UR cat delete pipe on with a totally stock exhaust and when it would rain the exhaust tone would change dramatically. My car would sound like a Subaru when it rained, well at least from the inside of the car. It was only when water was splashing on the exhaust though. If the road was just wet it wouldn’t do it, but if there was any standing water or it was raining hard it did it. Once I put my Buschur TBE on it went away. Never figured out what was going on….

 

Allright, so I got it narrowed down to two posible problems. It's either the fan being hit by water or the exaust ( I have a B&B turboback exaust with test pipe ). I found water in the air box that's why I thought somehow water did go through. But I guess it couldn't have gone past the MAF sensor. Anyway, I'll dig into this problem a little more.
Thank to everyone for your input.

 

i think its your exhaust. WHen I had my honda civic with a skunk 2 catback it rubbed on the chasis and in the rain it would make that same noise you described. It got even worse after I bottomed out and bent the midpipe.

 

Yea its been raining mad here in portland lately. We even had a wind storm last night , 60mph wind gusts around my house

Anyways im having same problem as you speak of, all kinds of drive train noises and my exhuast sounds deeper, more bassy now becuase i think the rain got into the muffler and ruined the fiberglass packing. Hopefully nothing to serious with me or you..

 

I'm glad I asked the question, now it makes more sense. I'm sure it's the exaust, I'm going to check the undertray just in case there's something loose that may cause even more noise from vibration.

 

I know I'm a little late for this post but tonight, I've notice the same problem with my 2005 evo 8. I have a greddy ti and burshur dp. I am almost convinced that it is the exhaust or dp causing it. Scares the crap out of me though.

 

Nice outfit on your myspace picture page... LOL got to love the pink.

 

haha if you ever want to borrow it lemme know, i still have it. Ace Ventura was the best costume ever lol. Every now an then it comes out on really drunk house party nights.