Rear Suspension Rattle

[Wheelspin]

My Ibiza has an annoying rattle coming from the rear. It's silent most of the time but rattles a lot on rough surfaces and is more of a knocking sound over speed bumps. I'm almost certain it's the suspension as a while back I removed the parcel shelf, spare wheel, tool kit, boot floor etc. to check it wasn't anything inside the car. With almost nothing left in the back the rattle was still there.

I looked underneath earlier for anything obvious like broken springs and everything seems fine, although there are a lot of small cracks in the rear axle bushes. I would expect the bushes to cause a squeak rather than a rattle though I could be wrong.

I'm on a rather limited budget so before I start throwing money at it replacing things in the hope they'll solve the problem, what's the most likely cause? I know you can't say for certain, so any help is much appreciated, thanks!

 

[tomatcess]

Is it more of a knocking or a rattle? I had the same with my first Ibiza and it turned out to be a pound coin that had fell into the little hole where the seats connect in the back!

 

[Wheelspin]

It's quite difficult to describe, it's more of a rattle I suppose. It's quite low pitched, like there's a large can of de-icer or similar bouncing around in the boot, even when the boot's empty.

 

[Risto]

Exhaust related? Broken hanger or heat shield slapping the boot floor? This is a long shot as what you've described is the rear, my Ibiza knocks/rattles as the front rear lower arm bushes have seen their day, which sometimes does sound like a knock coming from further back. They're easy to inspect, most probably wrong but just a thought.

 

[R3k1355]

If bushes on the rear are ****ed then thats the best place to start, they do knock when they go, you don't usually hear squeaking.

 

[Wheelspin]

Thanks for the suggestions, I had a look at the exhaust a while ago when I first noticed the sound and it seemed fine but I'll have another look to check.

The bushes did look a bit suspicious, each bush looks almost stretched on one side, and rather squashed on the other, with the squashed side covered in small cracks. I thought maybe they'd collapsed a bit but as they both look the same I then thought it was probably normal. Now I'm not so sure.

 

[Risto]

Let us know how you get on, if you can get a big lever bar in there see if there's any excessive movement.

 

[Wheelspin]

Well I've had a look underneath, all the exhaust hangers and heat shields are fine. One of the heat shields knocks against the fuel tank if I prod it but it's just the metal of the shield flexing rather than the whole shield moving, not something I think would happen when driving. The bushes also don't look as bad as I originally thought.

I took everything out the boot again, so there was nothing left to rattle. I went for a drive and it still rattled. So then I removed the tailgate trim and went for another drive and the rattle was quite a bit louder. I got my Dad to sit in the back and went for yet another drive, he confirmed the noise was definitely coming from the tailgate itself. My best guess at the moment is the gas struts because if I push the tailgate upwards when it's already open (as though I'm trying to push it further open than it should go) there is a very similar rattle/knocking sound and there's quite a lot of movement of the gas struts on their lower ball joint mounts.

Some time in the next few days I'll remove the struts and see if that cures the sound. If it doesn't, then I'm completely stumped!

 

[Risto]

Sounds like you've found the culprit, enjoy the knock free motor!

 

[Wheelspin]

I've finally sorted it out this morning. It wasn't the gas struts, it turned out to be the whole tailgate moving around. I've moved the striker inwards slightly to hold the tailgate closed more tightly. It has to be slammed to close properly but it's now completely silent apart from over the biggest bumps. Finally!