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Rattling noise - 2010 Corolla LE

Maintenance/Repairs
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#1

Greetings,

This is my 1st post here, but honestly I am not sure where else to turn with this issue. First, the background:

I purchased a used 2010 Toyota Corolla LE with about 40k miles back in February of this year. Since then, the car has been issue-free and has responded accordingly.

Two weeks ago I noticed that the car when idle or at a stop light it’d make a subtle rattling noise (as if it was something behind the glove compartments rattling against metal). At 1st I thought maybe it was something inside, but as that week turned to days, I noticed that while I was outside the car and it was on and idle, I could hear the rattling from the right side of the car under the passenger seat (closer to the engine, as if right below where the glove compartment sat)–It is a constant rattle at the same frequency…meaning it doesn’t rattle one way 1st and then another later. It sounds the same, but it is random.

It evolved from a subtle rattle inside to being a loud rattle outside under the car. I noticed that if it was rattling and I turned off the air, the rattling would stop, but after 20 seconds, the rattling would return just not as frequent.

It was advised to me that perhaps it was the blower…but the blower sits behind the glove compartment and should not sound so loud under the car. Not only that, but if the blower isn’t on (when I turn off the air) it shouldn’t sound…at least that’s my logic for it.

The sound is getting louder and more frequent at this time and I’m just not sure what to do about this. I live in Miami, FL and hearing so many rip offs at mechanics, I thought maybe taking it to the dealer would be a good idea…but then again I haven’t the slightest idea of how much it’d cost.

I don’t know what this rattling is and I’ve already crawled under the car and see nothing wrong, nothing shaking violently, nothing.

Any ideas? Thanks.

#2

Does the rattling change or go away with RPM change? Try kicking the tail pipe (really) if that produces the rattle it may be just a loose exhaust heat shield. I have fixed these with large hose clamps or just completely removing them.

#3

The only difference I can tell is that the faster I go, the more consistent the rattling gets. So rather than it be every now and then, it rattles much more frequent.

This morning on my way to work, it only rattled a few times in my 25 minute drive, but then again I was under 45 most of the time. During most of yesterday, however, I was driving from Tallahassee, FL to Miami, and going above 65 to 70 95% of the time. The rattle was more frequent and obvious.

I will test to see if it in fact is the tail pipe.

#4

Whether kicking the tail pipe reproduces the noise or not, I am pretty sure that you are merely hearing the effects of a loose or bent heat shield on the exhaust system. This situation is something that is not consistent, and can change with both engine speed and the operating temperature of the exhaust system.

The only way to tell for sure is to put the car up on a lift in order to examine the exhaust system while the engine is running. A helpful mechanic can usually remedy this problem with a clamp applied in just the right place. Do NOT allow anyone to remove the heat shield. If it wasn’t necessary, the manufacturer would not have spent the money to install it in the first place.

#5

I will try to see if playing around with the exhaust will reproduce the noise. I was also considering just taking it to a local Toyota dealer to have it inspected if I needed to take it anywhere.

#6
It evolved from a subtle rattle inside to being a loud rattle outside under the car. I noticed that if it was rattling and I turned off the air, the rattling would stop, but after 20 seconds, the rattling would return just not as frequent.

So it rattles with the car off, even?

If it rattles with the car on, I’d first look at exhaust’s heat shields. Get an automotive stethoscope and probe around.

#7

With the air conditioning off, it’ll rattle. The car has to be on to rattle though.

#8

Perhaps that puts a bit of load on the engine, causing it to run slightly differently and that happens to resonate with some piece of sheetmetal somewhere. Sound travels.
Get a stethoscope and probe around. One of these will help you retain your sanity:

http://www.harborfreight.com/mechanics-stethoscope-41966.html

If it does end up being a heat shield, you can often fix it by putting a large band clamp around it. They are very often mounted with sheetmetal ears that just rot away.
They sell the larger band clamps at Lowes and Home Depot’s plumbing department:
http://www.pipe-clamps.com/productsimages/12mmbandclamp_164865.jpg

Edit: I see @PvtPublic already mentioned that as a possibility. I agree. Look at that first.

#9

It could be something as easy as a pebble in the that shield. Had it happen to me a few years back.

#10

It was in fact the heat shield. I went to Pep Boys to get an under car inspection and the mechanic spotted it immediately and fixed it for me. Didn’t charge me more than the inspection itself, which was roughly 20 dollars.

Thanks for the help! Now I am driving rattle-free!

#11

Excellent news! Thank you for updating us.

Just be sure that you don’t go back to Pep Boys for anything more technical than clamping the heat shield. Their screw-up rate tends to be quite high (just like almost all chain operations), and something as simple as an oil change could be deadly in the wrong hands.

#12

Only reason why I took it there is so they could lift the car and look under it. Mind you, I was literally right next to the guy like a hawk. And they only charged me 20 bucks which I was willing to pay to get this monkey off my back. After asking so many people and doing some inspection myself…I just HAD to be sure.

I even called the Toyota dealer nearby and they wanted to charge me a lott o lift it and to look under the car…The moment I said “it’s out of warranty…but I just wanna take a look under it so I can get a second opinion…” the friendly tone from the lady on the phone changed and she wanted to book me for a 105 visit to tell me what was wrong…and according to her would have been a couple of hundred to fix it.

I asked various car forums and they all pointed me in the same diagnostic direction, so I was glad it was as quick and simple as it seemed.

#13

Totally agree with @VDCdriver: Don’t go to chains. Use an independent mechanic. Once you find a good one that’s honest, stick to him. They’ll take care of you.

Glad it ended up being just a heat shield. Thanks for letting us know how you made out.