Hum at low speed

[mash62au]

My Aurion AT-X (2009) emits a subtle, low hum between 30 and 50 kph. It sounds like something that's rotating or spinning that might be causing this sound. It's not loud, but is an irritant.

I had the 4 manufacturer-supplied Dunlop tyres replaced recently, by Bridgestone ER30, but this hasn't made much difference. The dealer acknowledges that they can hear the noise, but is unable to say what is causing it. My older 2004 Camry is a lot quieter (it has Bridgestone AR10 tyres on it). What else might it be? I don't hear it if I rev the engine or idle, while in park or neutral.

I don't believe it's the tyres - since I've just got new ones. What other rotational parts exist that could be emitting this noise? It sounds like it's coming from the front left side, but I can't be sure.

Are sound deadeners my only option?

[Steven]

My Aurion AT-X (2009) emits a subtle, low hum between 30 and 50 kph. It sounds like something that's rotating or spinning that might be causing this sound. It's not loud, but is an irritant.

I had the 4 manufacturer-supplied Dunlop tyres replaced recently, by Bridgestone ER30, but this hasn't made much difference. The dealer acknowledges that they can hear the noise, but is unable to say what is causing it. My older 2004 Camry is a lot quieter (it has Bridgestone AR10 tyres on it). What else might it be? I don't hear it if I rev the engine or idle, while in park or neutral.

I don't believe it's the tyres - since I've just got new ones. What other rotational parts exist that could be emitting this noise? It sounds like it's coming from the front left side, but I can't be sure.

Are sound deadeners my only option?

A low hum at certain speeds can be a possible indicator of worn wheel bearings, however your car is fairly new so it's just a idea. How many kms have you done? Further does the hum ever return louder when going 100km/h or more?

[mash62au]

The dealer's checked the wheels and hasn't reported any issue with the bearings. I've done about 45,000 km. No, the noise in fact seems to reduce (or probably isn't audible due to other noises such as wind, bad road surface, etc) at higher speeds. It is most audible at the lower speed mentioned. It's a hum, but sort of a fine, grinding hum. I'm no engineer, but aren't there other rotating parts - such as the bits from the engine that drive the front wheels? Not sure if the dealer has inspected all that. I will have to take it back to them to have a very thorough check.

[Steven]

The dealer's checked the wheels and hasn't reported any issue with the bearings. I've done about 45,000 km. No, the noise in fact seems to reduce (or probably isn't audible due to other noises such as wind, bad road surface, etc) at higher speeds. It is most audible at the lower speed mentioned. It's a hum, but sort of a fine, grinding hum. I'm no engineer, but aren't there other rotating parts - such as the bits from the engine that drive the front wheels? Not sure if the dealer has inspected all that. I will have to take it back to them to have a very thorough check.

I always take the dealer report with a grain of salt - they likely just check the bearings by looking for any movement or low level grinding with the wheels off the ground. A low hum is an indication of a lightly worn bearing that probably still has plenty of life left, but anyway other things include the drive shaft and CV joints, as well as the gearbox itself.

[mash62au]

The dealer's checked the wheels and hasn't reported any issue with the bearings. I've done about 45,000 km. No, the noise in fact seems to reduce (or probably isn't audible due to other noises such as wind, bad road surface, etc) at higher speeds. It is most audible at the lower speed mentioned. It's a hum, but sort of a fine, grinding hum. I'm no engineer, but aren't there other rotating parts - such as the bits from the engine that drive the front wheels? Not sure if the dealer has inspected all that. I will have to take it back to them to have a very thorough check.

I always take the dealer report with a grain of salt - they likely just check the bearings by looking for any movement or low level grinding with the wheels off the ground. A low hum is an indication of a lightly worn bearing that probably still has plenty of life left, but anyway other things include the drive shaft and CV joints, as well as the gearbox itself.

So if we can't trust the dealer, where can I have the car checked out properly? Any suggestions welcome.

[Steven]

The dealer's checked the wheels and hasn't reported any issue with the bearings. I've done about 45,000 km. No, the noise in fact seems to reduce (or probably isn't audible due to other noises such as wind, bad road surface, etc) at higher speeds. It is most audible at the lower speed mentioned. It's a hum, but sort of a fine, grinding hum. I'm no engineer, but aren't there other rotating parts - such as the bits from the engine that drive the front wheels? Not sure if the dealer has inspected all that. I will have to take it back to them to have a very thorough check.

I always take the dealer report with a grain of salt - they likely just check the bearings by looking for any movement or low level grinding with the wheels off the ground. A low hum is an indication of a lightly worn bearing that probably still has plenty of life left, but anyway other things include the drive shaft and CV joints, as well as the gearbox itself.

So if we can't trust the dealer, where can I have the car checked out properly? Any suggestions welcome.

Finding a quality mechanic is the bane of many a car owner, but I do believe you will receive better service at a reputable independent mechanic as opposed to a dealership

[Sunsett]

Can I assume that you have an auto V6 I believe we could have the same motor/trans in our RAV. I am in battle with Toyota at the moment re replacement (I will post soon)

TSB 0192-10

Sorry for the raw format, but it wont let me attach pdf files.

T-SB-0192-10 gear box whine.txt

Edited December 2, 2011 by Sunsett

[95celica]

from my experience there is one easy to determine the difference between tyre noise and bearing noise, tyre noise is more evident at lower speeds and wheel bearing as higher speeds. tyres hum and bearings growl, sometimes also have a squeek. If you feel the tread of your tyres, its should feel smooth, If it feels uneven (up and down like waves)usually on the inner edges, this can cause noise, some times the tread pattern ,especially directional tyres can cause noise, even when the tyre is new. Good brand, bad brands it doesnt matter sometimes. On one car I have had Bridgestone G Grids, they were noisy, on my other I have cheap chinese tyres, they are noisy too. Make sure you tyre pressures are right too. can make a difference. Hope you sort out your problem :D

[mash62au]

Can I assume that you have an auto V6 I believe we could have the same motor/trans in our RAV. I am in battle with Toyota at the moment re replacement (I will post soon)

TSB 0192-10

Sorry for the raw format, but it wont let me attach pdf files.

T-SB-0192-10 gear box whine.txt

You're right it is a V6 automatic transmission. Are Toyota refusing to cover it under the warranty?

[mash62au]

from my experience there is one easy to determine the difference between tyre noise and bearing noise, tyre noise is more evident at lower speeds and wheel bearing as higher speeds. tyres hum and bearings growl, sometimes also have a squeek. If you feel the tread of your tyres, its should feel smooth, If it feels uneven (up and down like waves)usually on the inner edges, this can cause noise, some times the tread pattern ,especially directional tyres can cause noise, even when the tyre is new. Good brand, bad brands it doesnt matter sometimes. On one car I have had Bridgestone G Grids, they were noisy, on my other I have cheap chinese tyres, they are noisy too. Make sure you tyre pressures are right too. can make a difference. Hope you sort out your problem :D

Thanks for sharing your experience. Tyre pressures are definitely right - I'm quite pedantic about keeping them inflated correctly.

Just came back from a drive. I noticed that at lower speeds, the whine has a very slight chopping sound at times. At higher speeds it's more continuous but not louder. It's very hard to describe. Just don't want this to be something bigger later on, so want this checked out.

[Sunsett]

My RAV has had full Toyota service history, 1 recall, but this problem was not picked up with the old owners. I stumbled on it and it is 6 mths out of warranty. Toyota have offered half the cost of $5500 fix. I am still in correspondence with them.

[mash62au]

My RAV has had full Toyota service history, 1 recall, but this problem was not picked up with the old owners. I stumbled on it and it is 6 mths out of warranty. Toyota have offered half the cost of $5500 fix. I am still in correspondence with them.

I'll get a second and possibly third opinion. Thanks.