Avensis T27 saloon Rattle noise from the back when stationary and windy

[Inpresmoj]

I've had my car a year and ive not been able to figure out what this noise is, its very weird

I hear it when going slow, or over uneven ground, its coming from the back somewhere and im guessing outside the car because i even hear the same noise sometimes when the car is stationary and there is a little bit of wind.  I don't hear it once up to speed.

I've been under the car and looked everywhere i can think of but cant figure it out

Has anyone had anything silimar or can suggest what things i can check. Thanks

[TonyHSD]

That’s interesting. You may need to go underneath again and thoroughly check all exhaust brackets, exhaust heat shields, suspension parts, stabiliser bar links particularly., bumper inside, and any plastic aero trims if you have any fitted. 
Good luck 👍

[Guest]

Sounds silly... but have you tried taking everything out of the boot, including the carpet, spare wheel any anything else that might have fallen down there and be rattling around?  (eliminate the easy things first?) 

[avetoy]

5 hours ago, TonyHSD said:

... bumper inside, and any plastic aero trims if you have any fitted...
 

Those are mine guesses too. And perhaps rear wheels plastic mud flaps might be loose?

[Konrad C]

The last time I had something rattle and even caused a bit of resonance, was when the heat shield dropped onto the rear silencer due to corrosion at the fixing points. I removed the shield and later did a repair and refitted. It may not look obvious until you look and reach under. The noise was more obvious at idle and low speeds, as stated by the OP. 

 

Edited April 8, 2022 by Konrad C
Additional info

[Inpresmoj]

great replies so far that gives me some things to check, I thought it might be the mud flaps to but they seem pretty secure from what I can tell.  The sound seems to be coming from rear left, ie passenger side.  Im going into Toyota in a few weeks to get something else sorted im thinking of asking to look under the car with a tec for a couple of minutes and see if we can see anything.

[2009joe]

14 hours ago, Inpresmoj said:

great replies so far that gives me some things to check, I thought it might be the mud flaps to but they seem pretty secure from what I can tell.  The sound seems to be coming from rear left, ie passenger side.  Im going into Toyota in a few weeks to get something else sorted im thinking of asking to look under the car with a tec for a couple of minutes and see if we can see anything.

I got a idea there is a plastic flap that lets air to get into around the boot etc u can see it when the rear bumper is off I'm sure as I seen those air vent flaps on cars before and we'll thinking if u can figure that's the problem .screw it shut or maybe put on that foam tape on to stop the slapping .tbh if that foam tape is on might leave flap open to let in creatchers .if me I'd try maybe screw it shut 

[TonyHSD]

Air vents best not to shut permanently, they are there for a reason although on avensis may not be a big issue. Yes, it can rattle from there but I don’t think it’s that. 

[2009joe]

9 hours ago, TonyHSD said:

Air vents best not to shut permanently, they are there for a reason although on avensis may not be a big issue. Yes, it can rattle from there but I don’t think it’s that. 

Could inspect them see if ok plus maybe close them see if the noise goes away .I have noticed with those stupid push in vents and other things after wiring in new Speakers upgrade that stupid clip in vent on the t27 2014 sqeeking a bit .why o why didnt Toyota like VW group not put in screws to secure those then a small plastic trim or something .or just have sliding pins like VW group to handy take out the radio to do upgrades .kina thinking might have 2 buy foam sticky strips to push in somewhere to stop those stupid small rattles and squeeks