Since I've owned my EL Futura it has made this wierd humming sound when travelling around 85 - 100km/h... I know sounds are hard to describe/interpret with words but bear with me.

The sound is not like a constant hummmmmmmmmmmmmmmmmmmm ... its more like a hummm humm humm humm humm humm (and so on...) the sound isn't terribly loud but is certainly noticeable and hasn't got any better or worse over the 1 year that I have owned the car. If I maintain a speed between 85 - 100km/h when it makes the sound it wont go away unless I speed up or slow down.

Sorry if it's hard to get what I am trying to describe, but does anyone have any ideas or suggestions as to what it may be? My car has 114,500km on the clock if that helps.

Thanks in advance, your help is always appreciated!

I don't know if this is the same sound or not but my auto EL gli made a humming sound when I was travelling 80+ and it was in 4th. I was going to get the auto serviced to see if that'd fix the sound but I ended up selling it. Does it happen to sound like vvvvvVVVVVvvvvvVVVVV (..lol)

yes it sounds just like that! I really don't know what it is

Is it coming through the stereo? Could be the capacitor on the side of the coil... Is it just coming from the car? Could be the auto... When you're doing 100 and you have the hum, just try pulling it from d back to 3rd and if the noise goes away then you know it is top gear in the gear box (common problem, but it more just a bearing noise than hum, which I would associated more with electronics than mechanics)...

Cheers,
Tim

It's sounds like something to do with the tailshaft, those speeds seem to be where most tailshaft hums occur.

Does it change at all if you back off the accelerator at those speeds?

Mine had a similar sound when I first lowered my car, it was caused by the bad diff pinion ange. That was fixed when I got the tickford arms to correct the angle.

That sort of sound can come from a few things. Uni joints, pinion angle, or the output bush.

Might pay to check your wheel bearings as well, my front drivers side is on its way out and is making a similar sound at about 80 - 90kph. Easy as to check, jack the wheel off the ground and give it a spin, if it's not spinning smoothly, you can feel or hear a grumbling sound, or you can move the wheel in and out any it needs replacing.
Mine is getting to the stage where I can feel it in the steering so once I get the new ones delivered they're going on. Best to replace both sides at the same time as replacing just one side will (in my experience) cause the other to fail within weeks Got both sides off E-bay for under $50 delivered.

I just did my wheel bearings a couple of weeks back, it's certainly not them... It is definitely a mechanical sound not an electrical one.... The sound doesn't seem to be present if i drop it back to 3rd ... but that may just be because the sound of the engine is louder in 3rd and I may don't hear the humming over the revving... not sure...

I was thinking it could be drive shaft related? I have noticed if I change from reverse to drive (or vice versa) in quick succession something along the driveline make a LOUD bang/clunk sound... it doesn't always do this but it has done it a few different times when i've accidently changed from reverse to drive (or vice versa) while the car is still moving slightly or if i've accelerated a little while changing gear (I know thats bad but I've only done it on accident)

could this be related to the humming sound? like a uni link or something?