Hi everyone,
I've recently finished my 318is s52 swap wrapped up and got everything mostly ironed out, but I was curious about the harmonics of the 3.2 as opposed to the 2.5 m50 that was recently in the car.
Around 3000-3500 rpm the engine seems to make a humming/droning noise that's quite tiresome on longer trips with the windows closed (not unlike a wheel bearing). Initially I suspected my driveshaft my be misaligned, but I don't have any strange vibrations. I plan to double check its alignment, but I'm 95% sure I matched up the white alignment marks between to the halves. The CSB is new as well and has been preloaded. With the clutch depressed at speed the noise goes away, so I'm led to believe it's engine and/or exhaust related. My swap was a long block swap, so my driveline components are the same as they were with the m50 for reference.
I do have a generic aftermarket muffler that's on the louder side, but didn't really drone with the m50. However, the exhaust was originally 1 piece from the downpipes through the muffler, but i chopped it after the cats to use a slip joint/clamp to make removal & install easier, so perhaps it leaks enough there, but the clamp is tight as can be.
The motor is essentially stock, including the front crank pulley dampener. My friend has a similarly prepared s52 car and his car doesn't seem to make quite as much noise from the interior. His car is a 325i though, so I wonder if the 325's factory sound deadening hides a lot of noises vs. a 318? I don't expect the car to be quiet like a new car, but it seems a bit buzzier than it needs to be.
I have an appointment at the exhaust shop next week to possibly install a quieter muffler, but if worse comes to worse, I'll add some sound deadening like dynamat or damplifier. Another item I have thought to experiment with is swapping the Condor UMHW 24v motor mounts out for rubber e28 units, but they only seem to make the car vibrate at idle.
I just wanted to check and see if anyone had some pointers or suggestions of items that I may be overlooking. Otherwise the car is a blast to drive and seems to be running strong.
Thanks,
Joey
I've recently finished my 318is s52 swap wrapped up and got everything mostly ironed out, but I was curious about the harmonics of the 3.2 as opposed to the 2.5 m50 that was recently in the car.
Around 3000-3500 rpm the engine seems to make a humming/droning noise that's quite tiresome on longer trips with the windows closed (not unlike a wheel bearing). Initially I suspected my driveshaft my be misaligned, but I don't have any strange vibrations. I plan to double check its alignment, but I'm 95% sure I matched up the white alignment marks between to the halves. The CSB is new as well and has been preloaded. With the clutch depressed at speed the noise goes away, so I'm led to believe it's engine and/or exhaust related. My swap was a long block swap, so my driveline components are the same as they were with the m50 for reference.
I do have a generic aftermarket muffler that's on the louder side, but didn't really drone with the m50. However, the exhaust was originally 1 piece from the downpipes through the muffler, but i chopped it after the cats to use a slip joint/clamp to make removal & install easier, so perhaps it leaks enough there, but the clamp is tight as can be.
The motor is essentially stock, including the front crank pulley dampener. My friend has a similarly prepared s52 car and his car doesn't seem to make quite as much noise from the interior. His car is a 325i though, so I wonder if the 325's factory sound deadening hides a lot of noises vs. a 318? I don't expect the car to be quiet like a new car, but it seems a bit buzzier than it needs to be.
I have an appointment at the exhaust shop next week to possibly install a quieter muffler, but if worse comes to worse, I'll add some sound deadening like dynamat or damplifier. Another item I have thought to experiment with is swapping the Condor UMHW 24v motor mounts out for rubber e28 units, but they only seem to make the car vibrate at idle.
I just wanted to check and see if anyone had some pointers or suggestions of items that I may be overlooking. Otherwise the car is a blast to drive and seems to be running strong.
Thanks,
Joey
Comment