Yaris 2010 knocking noise from rear RH suspension.

[wildtapholer]

This might sound like a daft question but have you checked the front drop links, in the car it sounds like it's coming from the rear when driving.

[Markoo]

On 6/27/2023 at 12:00 AM, Stevie J said:

...It could mean that the knocking noise may not be a suspension issue then, maybe something loose somewhere in the rear of the car. I think there is a void behind the tail lights that goes deep down behind the back wheel. It's accessible by removing the cover behind the tail lights as if you were changing a bulb, maybe something got dropped down there and is rattling about. Its a wild shot in the dark, and probably not the issue, but you have to investigate every area round by that back wheel area...

Hi. I think I have found it. It would appear that it is the rear bumper knocking against its metal beam. There is no isolation between them. I have stuffed some flat pieces of foam (kids old play area floor mat) and it seem to fix about 80% of noise (I need to test for couple of days yet). I guess I would have to remove the rear bumper completly and attach foam along whole lenght of metal beam to cure it. But it is progress nonetheless.

[Stevie J]

Thats very good, although I'm not sure what part of the rear bumper is loose though, I thought the bumper was entirely plastic, with a reinforced metal beam behind it. Are you saying the metal beam itself is loose and banging against the bodywork behind it? If that's the case, it may be that the car has been involved in some kind of accident before you bought it, and repaired poorly. It rings bells to me of the time, earlier this year, my last car, a Mk2 Yaris was hit from behind by someone who wasnt paying attention. It's an accident like this that may have led to someone just doing a superficial repair - enough for the car to outwardly look OK, but hiding damage that causes the symptoms you have had. Maybe taking the rear plastic bumper off and inspecting behind it may be a good idea - there may be more damage that you didnt know about. 

This is what my car looked like following someone driving into the back of me while in a queue for traffic lights - and it shunted my car forward into the tow bar of the car in front. The car was subsequently given a Cat B write off, and was scrapped sadly. As I didnt remove the back bumper, I didnt know how much damage had been caused.