Sensodrive strange gearbox whistle

I'm driving in 5th gear and there is a faint but noticeable humming/whistle sound coming from the gearbox. I know it's the gearbox as the noise goes away in neutral, changes with speed and disappears after shifting down to 4th. The whistle changes tone and becomes louder and deeper as the car slows down until it shifts down a gear and the noise goes away. The whistle disappears when accelerating and only happens when cruising or slowing down at lower speeds (30-50mph). At higher speeds it's gone.

Now over time it has gotten worse. The whistle has become louder and also happens in 3rd and 4th gear. Although it's faintest in 3rd, louder in 4th and the loudest in 5th.

Is my gearbox about to die?

I have tried changing gearbox oil but no change.

drummerdude wrote:I'm driving in 5th gear and there is a faint but noticeable humming/whistle sound coming from the gearbox. I know it's the gearbox as the noise goes away in neutral, changes with speed and disappears after shifting down to 4th. The whistle changes tone and becomes louder and deeper as the car slows down until it shifts down a gear and the noise goes away. The whistle disappears when accelerating and only happens when cruising or slowing down at lower speeds (30-50mph). At higher speeds it's gone.

Now over time it has gotten worse. The whistle has become louder and also happens in 3rd and 4th gear. Although it's faintest in 3rd, louder in 4th and the loudest in 5th.

Is my gearbox about to die?

I have tried changing gearbox oil but no change.

I wouldn't expect gearbox oil to whistle, but are you sure its coming from the gearbox?

Changed gearbox oil as have seen other places online recommending it for similar problems. It's cheap, so worth a shot.

I'm pretty sure it's the gearbox although I could be completely wrong. Reason I say it is is because the noise always changes depending on the gear it's in. The whistle noise is not there when parked and revving, disappears in neutral, disappears in gear 1 and 2. I can drive up to 30mph in 2nd and not hear the noise but as soon as I change up to 3rd/4th/5th, the noise begins.

I was driving today and it seems the noise is there even under light acceleration but not as much as deceleration. It seems quietest when the car is maintaining a constant light speed, I'm guessing when there's less load? Who knows.

Any ideas what it could be other than the gearbox?

drummerdude wrote:Changed gearbox oil as have seen other places online recommending it for similar problems. It's cheap, so worth a shot.

I see, and it wouldn't do any harm and may even help you diagnose a problem from inside by looking at the colour of the old oil.

drummerdude wrote:Any ideas what it could be other than the gearbox?

I can't think of what the problem is. When you drained out the old oil, was there plenty to come out (around 2Litres) and was it an acceptable colour and were there any metallic bits at the bottom of the drain pan?

drummerdude wrote:disappears in gear 1 and 2. I can drive up to 30mph in 2nd and not hear the noise but as soon as I change up to 3rd/4th/5th, the noise begins.

This bit is interesting as it does seem to indicate a problem with 3rd/4th/5th.

Would it be possible to record the sound? A mobile phone can usually make video clips with sound. It may help someone identify the problem for you.

C3driver52 wrote:

drummerdude wrote:Changed gearbox oil as have seen other places online recommending it for similar problems. It's cheap, so worth a shot.

I see, and it wouldn't do any harm and may even help you diagnose a problem from inside by looking at the colour of the old oil.

drummerdude wrote:Any ideas what it could be other than the gearbox?

I can't think of what the problem is. When you drained out the old oil, was there plenty to come out (around 2Litres) and was it an acceptable colour and were there any metallic bits at the bottom of the drain pan?

drummerdude wrote:disappears in gear 1 and 2. I can drive up to 30mph in 2nd and not hear the noise but as soon as I change up to 3rd/4th/5th, the noise begins.

This bit is interesting as it does seem to indicate a problem with 3rd/4th/5th.

Would it be possible to record the sound? A mobile phone can usually make video clips with sound. It may help someone identify the problem for you.

The oil was fine. Full 2 litres came out and it was a dull red colour. Not burnt or anything. No metallic bit or debris as far as I could tell.

I will try making a video on the sound soon and post it up. Appreciate the help!

drummerdude wrote: it was a dull red colour.

That's doesn't sound right for a sensodrive box, should be either white or golden yellow, maybe with a slight green tint.

Did it smell?

Do you have any left? Can you take a picture?

How did it compare with the new oil you put in?

Arfur Dent wrote:

drummerdude wrote: it was a dull red colour.

That's doesn't sound right for a sensodrive box, should be either white or golden yellow, maybe with a slight green tint.

Did it smell?

Do you have any left? Can you take a picture?

How did it compare with the new oil you put in?

It stunk badly, but so did the new oil - just not as bad. The new oil was a slightly lighter golden/reddish colour.

Don't have any left. That stuff stinks too much to keep around :L

Bear in mind that this car has 83k miles on it and has probably never had the gearbox oil changed.

C3driver52 wrote:

drummerdude wrote:Changed gearbox oil as have seen other places online recommending it for similar problems. It's cheap, so worth a shot.

I see, and it wouldn't do any harm and may even help you diagnose a problem from inside by looking at the colour of the old oil.

drummerdude wrote:Any ideas what it could be other than the gearbox?

I can't think of what the problem is. When you drained out the old oil, was there plenty to come out (around 2Litres) and was it an acceptable colour and were there any metallic bits at the bottom of the drain pan?

drummerdude wrote:disappears in gear 1 and 2. I can drive up to 30mph in 2nd and not hear the noise but as soon as I change up to 3rd/4th/5th, the noise begins.

This bit is interesting as it does seem to indicate a problem with 3rd/4th/5th.

Would it be possible to record the sound? A mobile phone can usually make video clips with sound. It may help someone identify the problem for you.

OK here it is. Made a video this evening.

https://www.youtube.com/watch?v=50A1PJW ... e=youtu.be

Arfur Dent wrote:

drummerdude wrote: it was a dull red colour.

That's doesn't sound right for a sensodrive box, should be either white or golden yellow, maybe with a slight green tint.

Did it smell?

Do you have any left? Can you take a picture?

How did it compare with the new oil you put in?

Any ideas mate? Forum seems a little quiet

BUMP