Hello all,
My 04 SC has a rattle in the passenger seat, where the seat cushion and the seat back meet, close to the passenger side door. It only rattles when nobody is in the seat. Washboard type roads are the worst but can happen with any bump in the road. Had the dealer look at it, did not find a problem. I did a search and it seems it was a fairly common problem a year or two back. Found mention of possible fixes including leather conditioner, loose wiring harness or just moving the seat all the way back so there is some pressure on the seat back from contact with the rear seat. I think this last thing works but I would much rather fix the problem than work around it. Any help is appreciated. Thanks, David

 

Try making sure lumbar support is fully extended in passenger seat. If it is not the seat will tend to "rattle" when there is no one seated in it.

 

I'll try that. Thanks

 

I have this problem too. And I can temporarily fix it by pulling the seat forward (as if a passanger should go into the back) and then push it back into place again.

This fixes the problem until you've had a passenger in the front seat.. Then you need to repeat the above procedure again.

 

I had the rattle too in my '04, but I had a different source. I heavily conditioned the seats when new (always dry), but have the seat all the way back but not touching (1mm or so), and have the lumbar completely deflated.
In my case it was the seat belt buckle; it's badly designed and can rattle when in its normal resting place. After I wedged it in such a way it didn't move, rattle was gone. One more thing to look at.

And talking about mysterious rattles, I had one that seemed to come from the back seat area near the headrest and tray; it was driving me nuts. Turns out it was the plastic cover over the pivot point in the roof. This piece of plastic can be seen with the trunk open, and it's right below the tray, on the most forward part of the trunk. I hate when you can't locate the source of a rattle.
Other than that, I have numerous rattles in broken pavement since the car has more cowl shake than it should, but are not persistent after the pavement turns smooth. We'll see about that in a few thousand more miles though; car just turned 1,000 this week, after 6-1/2 months of ownership. Definitely to blame are the run-flats, which is the equivalent of riding on bricks.

Good day people.

 

I have 600 miles on my SC430 and the rattle on the front passenger seat started at around 300 miles. It seems to be coming from beneath the cushion. I raised the seat all the way but did not see/feel anyhing aside from some wires. I will try to place some foam around the wires and see if it will help. I also have a rattle on the plastic trim right above the passenger side on the edge of the headliner. When I press on it, it stops. I hope no other rattle develops because it quite annoying. My ES is completely rattle-free...