Loud humming noise when letting off the accelerator?

[dann2707]

Hi!

I've developed this problem where when i'm accelerating and letting off the pedal, or sometimes it does it when i'm accelerating lightly I can hear this whirring, a high pitched one, imagine an owl noise but constant like a wheel bearing but no where near as drony.

The only way to describe it is a "hooooooooo" ?

It might be worth mentioning that my clutch is also going if that makes any difference?

Does anyone have an idea, trying to get some dashcam footage uploaded to show it! Thanks

 

[bozothenutter]

Manifold to cat joint?

 

[dann2707]

Manifold to cat joint?

What sort of sound would this give off? It sounds more mechanical than an exhaust blow but i'm all ears!

Thanks for the reply

 

[dann2707]

This is a video of it, Im sorry for the horrible sound quality. You can just about hear it when i'm letting off the throttle?!

 

[franx]

check all your engine mounts , when one of these has gone it could cause the engine to tilt when letting of the throttle , + then causing vibration/resonations . However you should also notice when hitting the gas ..?
Sound mechanical to me too anyway

 

[incy-spider]

Exhaust touching the underside of the car when letting off possibly, have a look under and see if there are any marks.

 

[dann2707]

Exhaust touching the underside of the car when letting off possibly, have a look under and see if there are any marks.

I've just had a gander but nothing out of the ordinary. How much should the engine be able to be moved as it seems fairly wobbly when i'm putting my hand on the engine and trying to move it.

check all your engine mounts , when one of these has gone it could cause the engine to tilt when letting of the throttle , + then causing vibration/resonations . However you should also notice when hitting the gas ..?
Sound mechanical to me too anyway

Cheers for that, as above really. Not sure how much resistance I should be getting when rocking the engine but i'm not hulk and it seems to move quite a bit back and forth. Dogbone is polybushed.

 

[incy-spider]

Does your gearstick move a lot when accelerating / de-accelerating?

 

[dann2707]

Does your gearstick move a lot when accelerating / de-accelerating?

I haven't noticed it when driving but I haven't been looking out for it. I'll check tomorrow when i'm driving to work.

What I have noticed is that it's hard to get into 4th and crunches quite a bit but I presume that's just because the clutch is on its way out. Need to get it changed asap

 

[franx]

it should only move like 2 cm or so (difference between all the way back + forth that is)

When you say "quite a bit" it sounds like you found a problem. When you say the dogbone is poly-d , then this one might be ruled out. The other one is visible from above when looking at it (left one) , which leaves the upper gearbox mount. This one needs the battery removed to have a look-see

 

[dann2707]

it should only move like 2 cm or so (difference between all the way back + forth that is)

When you say "quite a bit" it sounds like you found a problem. When you say the dogbone is poly-d , then this one might be ruled out. The other one is visible from above when looking at it (left one) , which leaves the upper gearbox mount. This one needs the battery removed to have a look-see

Oh is 2cm normal? I was expecting like 2mm or so haha. Seems to be normal then. The soudn is definitely a whirring like something going around rather than a mectal on metal sound like what would be with the exhaust hitting something etc, or from what I can gather anyway.

 

[incy-spider]

Take it to a garage.

 

[dann2707]

Take it to a garage.

That's cheating and it's intermittent