mysterious sound?

[Neoinwales]

My 2016 XC90 passed MOT without any advisory. But there is a mysterious sound comes from somewhere in front, just one light bang or clunk in these conditions (so far) -

1) Reversing to my driveway (my drive has a slight slope. I need to turn the steering wheel to the left first. When returning the steering during reversing, I can hear the light bang or clunk. It is not loud, and only once.)

2) Sharp right turn with body rolls (If I make a sharp right turn, even though at low speeds, I can hear the same sound).

I took it for a diagnosis at a local garage (not volvo). They only found slight play in n/s inner rack arm and also told me they are not sure that's the cause.

Anybody can give some advice where to look into? Thanks in advance!

[Philip Fisher]

Originally Posted by Neoinwales

My 2016 XC90 passed MOT without any advisory. But there is a mysterious sound comes from somewhere in front, just one light bang or clunk in these conditions (so far) -

1) Reversing to my driveway (my drive has a slight slope. I need to turn the steering wheel to the left first. When returning the steering during reversing, I can hear the light bang or clunk. It is not loud, and only once.)

2) Sharp right turn with body rolls (If I make a sharp right turn, even though at low speeds, I can hear the same sound).

I took it for a diagnosis at a local garage (not volvo). They only found slight play in n/s inner rack arm and also told me they are not sure that's the cause.

Anybody can give some advice where to look into? Thanks in advance!

I have similar. Usually only once and when the car is moved after resting for a bit. I wondered if it was the brake pads moving in the caliper. My car too recently flew through the MOT with no advisories. I asked about this noise and they investigated and agreed with my brake pad diagnosis.

[Neoinwales]

Originally Posted by Philip Fisher

I have similar. Usually only once and when the car is moved after resting for a bit. I wondered if it was the brake pads moving in the caliper. My car too recently flew through the MOT with no advisories. I asked about this noise and they investigated and agreed with my brake pad diagnosis.

Mine is definitely not from brake pads as it only occurs when steering wheel is turned (to the right).

[OldEngineer]

I'd vote on pads. If you change direction after braking to a standstill the pads will clunk in the calliper. Turning the steering wheel is just loading up the tyre so the unsquirming will amplify the wheel movement to make the sound louder.

[watto64]

Could be an anti-roll bar drop link that is worn at one of the ball joints, check the little rubber boots for splits or perishing. They tend to preferentially wear on one side due to repetative load bearing such as tight turns onto and off drives!

[Neoinwales]

Originally Posted by watto64

Could be an anti-roll bar drop link that is worn at one of the ball joints, check the little rubber boots for splits or perishing. They tend to preferentially wear on one side due to repetative load bearing such as tight turns onto and off drives!

This is my main suspect as the sound usually comes out when the vehicle has some degrees of body roll.

[neilgorin]

I had a knock like that on my v70 when the miles got up.

Tried changing drop links, didn't make any difference.

Passed the MOT without comment but the tester himself said he'd seen lower joints fail on these cars without any movement he could feel.

Had the lower ball joint on one side replaced (whole lower arm in fact, wasn't very expensive). Noise went.

However, I would vote for pads in your case.

[Neoinwales]

Originally Posted by neilgorin

I had a knock like that on my v70 when the miles got up.

Tried changing drop links, didn't make any difference.

Passed the MOT without comment but the tester himself said he'd seen lower joints fail on these cars without any movement he could feel.

Had the lower ball joint on one side replaced (whole lower arm in fact, wasn't very expensive). Noise went.

However, I would vote for pads in your case.

Thanks for sharing the information. Lower ball joint could be the cause. 79k miles nearly I guess those joints and bushes are tired.

[OldEngineer]

Except the original poster said one single knock on the drive. Ball joints and other suspension bits would knock on the road and probably not on the drive at low speed.
It's just diagnosis of the evidence. So pads.

[Neoinwales]

Originally Posted by OldEngineer

Except the original poster said one single knock on the drive. Ball joints and other suspension bits would knock on the road and probably not on the drive at low speed.
It's just diagnosis of the evidence. So pads.

I have heard sound came from pads sometimes after washing the car and leaving it on the drive. You would hear a sound soon as the car moves. If you meant that kind of sound, it is different. XC90 weights around 2 tons (not sure though). it sounds like a metal touching when the body weight lands on something. But it usually occurs when the car turns. When driving in straight line, even on uneven roads, no sound or at least I can't hear it.