Hey guys,
in the last few weeks there's been a weird new noise in the bf mk2 ghia thats driving me insane. Have a listen here http://picosong.com/V8hZ/ It's a little hard to hear but its the slight vibrating sound that happens every few seconds. Might need to turn the speakers up a bit.

* Noise only happens while accelerating, not while braking or idling.

* Doesn’t happen while cruising along or at any speed above 50/60. Only happens while starting to accelerate after a stop sign or give way or something. If you take your foot off the accelerator while the noise is happening it stops and if you push your foot down harder while it’s happening it also stops.

*sounds like its coming from the rear or the middle of the car however it’s hard to pinpoint which side.

* There’s no unusual vibrations in the car while the noise is happening, no loss of power or anything unusual.

*when going up a large hill the noise will sometimes continue all the way up the hill until the surface evens out. Normally the noise just happens for 3 or 4 seconds while accelerating and doesn’t happen at all while just idling or cruising.

*Best way to describe the noise would be like a vibration like a thin piece of metal vibrating against another piece of metal.

There has been some work done on the car lately. New diff oil was put in (Nulon 80w-140 full synthetic) and a ZF transmission service with a bypass. Noise started about a week or two after these things were done.

If anyone has any ideas or has heard this sound before and knows whats up then any help would be really appreciated.

Cheers