I was just reacting to some one's post on the Jazz thread on the possible cause for his newly developed rattle when I realized that a thread dedicated to rattles might be interesting & even informative.
The problem is that debugging a rattle takes time and it is a negative labour - you make something go away after long effort. SAs don't spend too much time figuring out a rattle, therfore.
All current rattle threads are model specific. The is no reason to think that best practices from one model are not applicable to other cars. Hence this thread
1.
Car: Toyota Innova Crysta
Model Year:2016
Symptoms: dashboard booming & rattle
Fix: Tighten engine cowl
In my 6 month old Crysta, there was a booming sound and rattle "from somewhere on the dashboard" under acceleration. I told the ASC with very little hope of a fix. Turns out that this was a known problem in the first set of Crystas and localised to the engine cowl not being fixed right. They fixed it without issues. Might even have been a soft service advisory.
2.
Car: Honda City
Model Year:2003
Symptoms: persistent tick-tick rattle
Fix: Loose screws in audio slot
This low volume, inconsistent rattle in my Honda City was driving me nuts. No pattern to it. Could start and keep happening on a butter smooth highway. Not happen at all on really bad roads. Start & continue for days. Stop in 2 minutes.
I wasted a lot of time figuring it out. Dakshin Honda all but asked me see a psychiatrist for "hearing things". I gave up but finally found the cause: a couple of black screws loose in the accessory box.
Gather around, children,while I explain the cause. These were the bad old days when even 'premium' cars did not have an ICE standard except in top variants. The 2 Din slots came with cutouts but the most common head units were 1 din. So if you installed a 1 din ICE there was this gaping hole in the dash. Installers who thought things thru cut only half of the cutout so there is no hole. But it still looked ugly.
Honda had this solution for this problem: they sold you a very well engineered box that fitted into the 1 din slot, screwing into the same points an ice would have. It had a nice, soft dampened door and make the dash look good. Only issue, they engineered it so that it was
just smaller than a CD. So it was basically useless but looked good. Today, a smart phone would fit there. The Nokias of those days laughed at you.
This a picture of the box:
So there was this 6 inch deep useless box on the dash that you will never look at after you installed it (that was the function of it). I had my 'log book' in that place. Some installer had put in 2 black screws into this box. So, you have 2 invisible screws (searching for a black cat at midnight on a new moon day in a coal cellar has nothing on this one!) in a black, useless box. So the screws rattled all the time. But when they got on top of the log book or in the spirals, they did not. They fell off when ever I removed the log book, thus escaping detection.
Big relief when I found out & removed them! Honda really should have rubber lined the box.