[autoxerwgn]

Well it's hard to say if your car is sounding "normal" but I can say that I have owned a E30 318is in the past, and when the M44 was still in the ti, the 4 cylinder engines are a bit louder than their 6 cylinder counterparts. With the M44, BMW even made changes to try and quiet things down like the big foam intake tube and a bunch of foam insulation in the airbox.