Springy, clattering noise

[cla5h]

Coming from rear of car, prob drivers side, but could be more central.

It's a light metallic sound - like a loose under-tray, but driven without rear undertray and diffuser, and noise persists.

Happens whenever I go over a bump. First noticed about 2 years ago, and has been getting gradually worse. Typical town driving now causes it to clatter loudly pretty much constantly.

Presumably not suspension components, as car passes MOT without issue (and both rear dampers have been replaced within last 1-2 years anyway.)

Have heard mention of heat-shielding coming loose, but I've poked around a few times, and never been able to spot anything obviously loose. Not sure if this material would give the 'metallic' noise anyway?

Any suggestions?

[steve_weegie]

Scott,

The exhaust manifold heatshield is a piece of sheet steel that can become corroded and rattle about against the exhaust, possibly making the sound you describe... Try poking about at the back of the engine, in the bulkhead area to see if it's developed some play.

Cheers,

Steve

[Rich H]

My S1 does that! sounds like a loose spring and jingles sometimes over bumps, buggered if I could find it, no loose bolts, no loose heatshields I just gave up looking!

[cla5h]

Had a feel of the heatshield round the manifold and downpipe. Seems fairly well secured - certainly hasn't broken away from its fixings.

Squeezeed my hand down between it and the bulkhead, to push against the bottom of it, at the edge away from the fixing, and there is some movement (I can press it back against the exhaust, and it does make a noise when there's contact.)

However, I can't see how normal driving would cause sufficient movement to lead to the clattering noise I'm hearing (unless the exhaust was free to move against the heatshield, rather than vice-versa.)

Any other thoughts?

[Shug]

Bear in mind that the engine will move quite a lot even in normal driving. My money would still be on a heatshield.

[Rich H]

Decat?

[cla5h]

Decat?

Granted, at high revs and with the stereo up very loud, the noice isn't noticeable, but the rest of the time, it does spoil the enjoyment a tad.

I'll have another look around the heatshielding, and see if I can bend it away from the exhaust a little.

[cla5h]

Had another root about, wedged anything I could find that looked like it could bounce against another surface, put it all back together, noise still there.

I give up - I'll wait for something to fall off, and turn the stereo up in the meantime.

[Stewart]

I had a similar noise after I fitted harnesses into my S1. The culprit was the loose seat belt warning (now) unused terminal hang loose against the floor. I couldn't believe that this was what was creating the noise but I tidied it up anyway and sure enough the annoying light rattle disappeared.

If you have checked everything else out it may be worth taking out the drivers seat to see if there is anything rattling against the floor. (the passenger one is more of a pain to get out)