Identifying a rattle

[Drew106]

Hi all,

Hopefully someone can help me with a rattle which is proving hard to identify. Always difficult to describe noises from cars, but let me try my best:

Appears to be coming from under the passenger foot well.
It is intermittent, not rhythmic.
Happens when driving over rough roads.
Almost sounds like something loose clattering - like a 'kat kat kat' every so often.
Driving and road handling does not appear to be effected.
Cannot replicate it by bouncing on the car, so doesn't appear to be suspension related.

So far what I've done is as follows:

Lifted the car onto axle stands and shook the wheels - all seems good.
Had a good look around underneath for anything loose - nothing I could find.
Took both fronts off to inspect - again nothing I can see lose or badly worn (not a mechanic though).

So anyone any ideas?
Car is a 2009 Hyundai i20 1.2 Classic.
I've read online about steering rattles which are a common issue on the i20, but I'm not sure what this should sound like. It doesn't strike me as a steering noise, but failing any other ideas, this could be the cause.

I'm thinking of selling the car soon, so a noise like this would certainly put people off.

Bit of a novel there, sorry! Thanks for reading. Any help appreciated.

Andrew

[Martin350]

It's always difficult to diagnose a noise from words rather than hearing it, and even then it can still be difficult sometimes.

My first thoughts would be to check the anti roll bar drop links, the ball joints should be quite stiff to move my hand (you can even disconnect them and drive the car over bumps to see if the noise has gone) and the exhaust heat shields, give them a tap and see if they are loose at any fixing points.

That's where I would start from your description.

[Drew106]

Martin350 said:

It's always difficult to diagnose a noise from words rather than hearing it, and even then it can still be difficult sometimes.

My first thoughts would be to check the anti roll bar drop links, the ball joints should be quite stiff to move my hand (you can even disconnect them and drive the car over bumps to see if the noise has gone) and the exhaust heat shields, give them a tap and see if they are loose at any fixing points.

That's where I would start from your description.

Thanks for the reply. Yes always a long shot diagnosing a noise on description!

Thanks for the tips though, some more areas to consider. It is due an MOT shortly, so I'm hoping to get to the bottom of it.

[E-bmw]

As above, they are prime candidates, just remember when checking bushes/joints the car will put much more force into a joint that a hand can. Use a long pry-bar/strong arm etc. to try to move the joint.

[66mpg]

Today I was asked to diagnose a similar problem with a Corsa. I found a piece of the offside front coil spring sitting in the spring cup which rattled every time the car went over a bump. The spring had snapped about four inches from the end and there was no obvious change in the ride height of the car.

[Martin350]

That's a good shout, I've also found that on a few cars.

And it's usually quite easy to spot a broken coil spring, with the car jacked up and the wheel off, even if the snapped off bit has escaped, so definitely worth checking that too.

[Mignon]

Your noise is typical of a worn ball joint in which there is now some play between the cup and the ball. Such joints can be found in the suspension control arms, anti-roll bar links and track rod ends. Once they get to the stage of making noise over rough roads they should show up at MOT time although on smooth roads you probably won't notice anything wrong and you certainly won't find them by bouncing on the car. Bottom ball joint would be favourite followed by anti-roll bar links. Track rod ends generally don't make noise over vertical bumps because that's not the direction they are loaded in.

[Drew106]

Thanks for replies everyone.

Sounds like anti-roll bar links are coming up a lot. Also recommended by some guys over on a i20 forum.

How would I test this to make sure before ordering a replacement? Or is it a case of change it and see if it solves it? They are pretty cheap at c. £15 so it's no real problem to do this.

Also, should I replace both sides, or is it OK to just do the worn one?

TIA.

[Winky151]

For the cost & general ease of replacement just change them. You can't tell what they're like until they're off anyway.

[Drew106]

Thanks, yeah I figured that myself. Just waiting on parts being delivered.

[Drew106]

Good advice guys, thanks.

Anti roll bar drop links changed and rattle gone. Should have been an easy job, but turned out to be a nightmare due to seized bolts and inadequate tools. Brute force and perseverance prevailed.

[Mignon]

Good result. Thanks for letting us know.