Honda Civic EX, standard trans, 1999, 103,000 miles.
We had some serious rain here this weekend. I took the car out on the second day of the rain and whenever I pushed on the accelerator it made a very loud noise - - sort of like there was no muffler attached or I had replaced my beloved Honda engine for a Harley! The acceleration is fine, just LOUD. It has since dried out and the car is still making the weird noise. If I put the car in nutral the sound is completely gone, if I release the accelerator, it lessens but does not leave. I tried travelling with cruise control and the sound was distinctly less.