Okay this may be the wrong place to ask this question but I figured maybe some of you know about cars. I drive a 90 Nissan Maxima, so I know it will make funny sounds and stuff will break and what have you, it's all part of owning an old car. However, a couple of days before I left for my cruise, I noticed that when I accelerated, the engine sounded louder than usual. Now it's really loud. It sounds like a motorboat or a go-cart. There is no change in performance, it doesn't hesitate, stall, or anything like that. It accelerates normally aside from the obnoxious sound. It also idles quietly, it's only loud when I press the gas. It seemed to happen practically overnight, it went from normal to loud within a day or 2. I tried putting a quart of oil in, I'm almost due for an oil change, but that didn't do anything. I really can't afford to get it repaired right now since I just blew a lot of cash on the cruise. Any idea what might be causing the noise?