Rattling sound on Yaris when A/C is off

[Yaris044]

I own a toyota yaris 1.3 automatic. I have a weird rattle sound when idle and very noticeable when starting acceleration but only when the A/C is OFF. As soon as I turn A/C on, the rattling sound disappear.
Maybe something with the A/C?

[ex-x-fire]

Most likely the a/c compressor clutch.

[06YarisRS]

In my 2009 Yaris 1.5 a metal AC line on the passenger side of the engine bay was almost touching the body of the vehicle at one spot. The line would often rattle against the body on acceleration, it was extremely annoying. The rattle would come and go depending on the temperature and whether the AC was on.
https://photos.app.goo.gl/eXzseCzwWiTwVe8F7

Nothing a pry bar wouldn't fix. I twisted and contorted most of the tubing in my A/C system to make room for both my engine swap and turbo kit install. Never developed any leaks as a result. The aluminum tubing is fairly receptive to being bent so long as it doesn't kink, I guess.

[06YarisRS]

Thank you for the advice. I tried to bend it a little, but was too scared of breaking it, so ended up just sticking a piece of polyurethane tape to the body to dampen the vibrations, I will give it another try. It appears that the root cause of the issue is the horizontal portion of the tube that somehow got bent outward. https://photos.app.goo.gl/dY9AuFFvF4yst18U9

I have no idea why the horizontal portion is bent, the vehicle has not been in any major collision.

I had a look at your pic, but can't tell where it's contacting. I used a combination of small wood blocks and a crowbar, wrapped in cloth to do my bending.
That horizontal tube can be moved back and forth in the little plastic retainers. Can you maybe indicated on a copy of your pic where the contact is? Nice clean engine bay, btw. :thumbsup:

https://i.imgur.com/yAGneWH.jpg

[06YarisRS]

May I ask how did you arrange the wood blocks and the crowbar to do the bending?

Thank you, I have recently purchased this vehicle from a dealer, it came with clean engine bay. I would not clean the bay myself. By the way, this Yaris appears to have the same problem as your new RS: the areas of the body where the axle arms attach are pretty rusty, although they are not perforated yet.

This should be an easy fix. You should just be able to hold it with your hands and bend the pipe out. You will only need to come out 1/8" to 1/4". I bent that exact section down about 3/4" after my engine swap, as there was too much strain on the rubber hose end that attached to the compressor.

https://i.imgur.com/1umheU6.png

As for the rust at the subframe, my advice would be to get some oil or some other thin oil-based substance in there soon. Rust Check "red" in cans would be perfect. I'd literally unload half a can in each side. It may drip out, so putting an old blanket or something under there might be a good idea. The oblong rubber plugs just outboard of those supports should access the inner cavity. When I am done welding, I plan to drill a hole at the lowest part and install a 1/2" plastic plug. That way I can access the area easily when I do my twice annual rustproofing.

Addition: If you do take out those rubber oblong plugs, you might note that the area is filled with sand and debris. I took the equivalent of about a cup of sand and crap out of each side. This is the 'design flaw in this generation of car (hatch, not sure about the sedans). That stuff in there holds water like a sponge.

[06YarisRS]

Thank you for your help. I have bent the tube away from the body, and now the tube is at a safe distance of ~0.5" or so from the former point of contact.
https://i.imgur.com/er0Maw9.jpg
I am going to remove the oblong rubber plug and spray this product (https://www.rustcheck.com/product/rust-inhibitor/) into the body cavity on each side. How does the debris get into the cavity? Would drilling a hole in the lowest part of the cavity automatically make the vehicle fail the provincial inspection?
https://i.imgur.com/PQW3Vlu.png

Yes, that rubber plug. Maybe poke around the other side of the axle arm support and see if there are any access points to spray in your rust check. I think there might be a small access point or two. I doubt that an inspection station would even know that a plug was not a factory plug if I do drill and plug a hole. I am not positive how the junk enters that cavity, but I expect I'll know by the time I've finished repairing mine. I just have to practice more welding of very thin metal before I start the reconstruction.

Good to hear that your A/C noise is gone. I hate rattles, creaks, clunks and any other sounds that are not supposed to be there. Haha. Oh, and your car is in great shape back there, unlike many from the Maritimes. We seem to used an astronomical amount of road salt here. I think the DOT operates under the assumption that if they don't use all their salt in a year, they won't get budgeted as much the following year. I've seen them dumping salt on dry roads with no weather forecasted. End-of-rant. :laugh:

[06YarisRS]

Back in Edmonton they would mostly use rocks instead of salt, not a much better alternative with all the chipping and ensuing rust.

Thank you, you are very friendly and helpful, I will keep an eye on your engaging detailed repair blog. I first found this forum in 2012, it brings back many good memories, so glad it is still alive.

You're very welcome, my friend.

I would prefer rock chips as they are on the outside and can be touched up. The salt is so insidious once it gets into the inner panels.

[06YarisRS]

Konstantin88, please check out my Red Yaris restoration thread. I discovered how you can access the large inner cavity that is prone to rust.

[komichal]

Just sharing my experience with rattling sounds with AC engaged and idling.... It was the exhaust heat shield that rusted off and with specific engine revs (hot engine, AC on, idling) it got rhytm and started shaking like mad. I took it away completely and driving a few years since then.
I know that this is not the case for your OP but someone may find this thread later when searching for answers.