Hey,

Has any one experienced a loud rattle coming from the trunk/rear end of the car? I have a 2004 SE3P 5-speed (Japan) with 108k km on it. The rattle started recently and seems to be getting louder and louder over time. I only hear it going over bumps (even small ones), and it sounds like a kettle with a loose lid bouncing around my trunk. I don't have anything in my trunk that would normally make that noise, and i checked all the screws and everything seems to be tight. The exhaust doesn't hit any thing when i move it around. Any ideas?

 

My first suspect would be a loose heat shield on the catalytic converter. Once they get loose they make all kinds of noise. You have to bang on it (preferably after letting it sit all night so you don't burn your hand) to see if it rattles.

 

Kevin, give the rear muffler a good whack ,or maybe the heat shield above it is loose. Are all the rubber hangers in good shape.

 

how do you fix it?

 

The noise over small bumps like out of driveways and a minor pavement variation was really irritating. I noticed when autocrossing under sharp corners also an occassional noise.

It got alot better when I changed tires. BUT it was still there.

I took the car back to Mazda to have them inspect all the bushings. They discovered that when they replaced my struts last month the tech didn't tighten the lower bolt on rear passenger side and it was backed almost all the way out. Ooops. Well it didn't hurt anything and the noise is completely gone now. At least the Service Manager was honest about it and of course no charge.

 

I finally totally resolved all rear suspension issues today.
I had the rear springs FE02-28-011 and bumpstops F152-28-1A1A replaced with factory originals. Red paint dot code. Also replaced the top rubber leaf spring F151-28-012A.

They have the same 13.5" free length and red paint dot as my old ones but they pushed the rear of the car up about 1.5" so I can now get less than -2* camber, the car rides great and no more noises when loaded and hitting minor pavement deflections.

**If anyone is psycho enough to want the old springs that can only get a minimum of -2.1* Camber in the back let me know. You can have them for the cost of shipping. They are still painted black here in FL and legal to use in SCCA Street as far as I know being original. They will drop the rear about 1.5" from stock.

 

So I am having what "sounds" like a similar issue except that I don't hear the vibration over every bump in the road. I only hear it over a certain type of bump and load in car. Its not even always the biggest bumps that cause the vibrations. Its a certain type that, I am guessing, creates a specific harmonic that causes it. And its only on my right rear wheel as well. It almost as if the wheel is bouncing. Another thing that only happens on that right side is a little wheel hop when taking a right hand corner from stop and accelerating fairly hard.

So naturally I thought perhaps my control arm(s) bushings were worn or my shock was blown. I decided to address the bushings first as I had fairly recently (about 1.5 years ago) upgraded my suspension to the Tein Street-Basis coilovers and I hadn't been doing any real rough driving (such as racing or autoX) to wear them out so quickly. So I replaced the rear bushings with Urethane versions...... This did not solve the problem, but I noticed an improvement in throttle response and handling

Next solution was to check the shock. I pulled it out, did a physical inspection (applied some pressure to the rod and it evenly compressed), visual inspection, and even contacted Tein as to what I should be seeing if the shock was ruined. They came back with a response saying it appeared to them like nothing was wrong but I should swap it with the other shock on the other side of the car to see if the problem migrates....... It did not and the problem persisted on the rear right side .

From here I have a couple more ideas but I was hoping someone may have had a similar experience and can point me in the right direction. Here are my ideas for where the problem is:

1. The other ends of the control arm where they connect to the wheel hub. I though that these were just mechanical pin connections without bushings. Have these been damaged or worn on other people's cars? To check this I put some leverage on the hub at several different angles with a 2x4 but I couldn't get it to budge in any direction it wasn't supposed to.

2. Bearing in the Hub. Have these historically worn out on other peoples cars? Anyone replaced one of these before? Maybe I am better off buying a new hub assembly....

3. Differential Mounts. When I was searching for control arm bushings I also came across urethane differential mounts. This got me to thinking that the stock ones must wear out but I don't really know the criteria of what I would be feeling if they were.. Perhaps the vibration I have been feeling is of the differential moving only under that certain harmonic? Any maybe the wheel hop occurs if the differential is free to move too much?

Too many questions. If anybody has has any experience similar to this I would love to hear it. Thanks!