Volkswagen Golf - Gollf mk4 making a 'roaring' noise accelerating - Matt5860
Hi, yesterday my car started becoming very loud like a roar when accelerating, in 1st and 2nd gear it was worse.
When I parked up, I noticed a rattling noise from underneath the car, it wasn't too loud but there was definitely some rattling from somewhere. Does anyone know what this could be? Catalytic converter?

I didn't notice any drop in performance and no warnings lights but I wasn't driving it for long after I noticed it as I was close to home.

If it is the cat, does anyone know much it should cost on the mk4 to replace?

Cheers
Volkswagen Golf - Gollf mk4 making a 'roaring' noise accelerating - edlithgow

Some people pay good money for that.

Cat's probably OK. I'd guess exhaust manifold flange gasket. Made my asthmatic 3-cyl sound quite muscular.

Could also be induction noise if something is loose in your air intake path, (depands on the roar) but the rattle suggests not.

Volkswagen Golf - Gollf mk4 making a 'roaring' noise accelerating - liammcl

Mine rattled when one of the suspension rubbers broke (£2)
and it was hitting the metal heat shield under the car.

I'd start the car when it's not hot,
and push and pull the exhaust from underneath at the side, and at the rear,
..it'll soon become clear where the noise is coming from.

It'll probably be where the pipes connect, hopefully a loose nut

Eurocarparts or ebay is a good place to get ideas of prices
(not GSF anymore, as they are giving silly 53% off...but thei rprices are over 53% added compared to eurocarparts etc. Daft marketing idea, imo, as newbies will be paying nearly double if they doin't have the voucher code. and will probably never go back)

Cheers
Liam

Edited by liammcl on 20/03/2017 at 01:18