Rattling noise

[JonGrose]

Hi,

When I first bought the car a year ago it had a rattling noise under the car/engine bay. I got a mobile mechnic to look at it and he said the 'Cat' under the car wasn't a official citroen one and just one that someone fitted. He welded it and the noise went...anyway, about a few months ago the noise it back. Is this simply the same problem that the cat needs welding again?

Also I read online about 'cat's that 'bolt on', is my car able to use these types as I'm new to car stuff.

My car is a 1.1 petrol 3 door 2000 reg.

[Ben_SaxoForte]

It's very difficult for anyone here to comment seeing as we can't actually see it, maybe it would help if you had a photo of the underside. Usually all catalytic converters on saxos are 'bolt on' so I'm not really sure what you mean by welded on unless it's some kind of aftermarket bodge up.

[stevo67]

Loose heatshield or rattling baffles?

[Shadowslayerzz]

It's possible you have the same problem I did, except my problem was my own fault lol, where the section of pipe is between manifold flange and middle box or cat there is an anti sway bar, if I remember rightly Citroen manufactured them as straight bars up until the 02 models, check to see if the exhaust is rubbing on the anti sway bar, there is also another couple of anti roll bars under rear axle that can sometimes rub on the exhaust is the exhaust isn't seated on the rubbers propperly.
Only other things I can think of is either gearbox mount for manifold has come loose or spring washers are the wrong way round on manifold connection to centre piece, all worth checking as they're easy jobs to fix and cost next to nothing :)

[Ollyc90]

there is also another couple of anti roll bars under rear axle that can sometimes rub on the exhaust is the exhaust isn't seated on the rubbers propperly.)

Those anti roll bars are the rear torsion springs....

If something is banging it will leave shiny metal, check your exhaust, if something is hitting it'll be clean in one place. Bang the exhaust, if you have a loose baffle you will hear it