When i originally got the car the engine was relatively quiet, ok you knew at idle but you just got a loud growl at revs.

However now the car sounds more like a ford transit, especially when accelerating. Its probably my imagination but its not as keen when revving and i have to push my foot down further to get the kind of acceleration i remember getting.

Its done 72'000 in about 4 years now, which i know really isnt much for a diesel but never owned a diesel before do they all seem to turn into a JCB engine as they got older?

That low growl is something I got when I had vacuum related issues. You might be suffering from sticky vanes on the turbo (not too common thankfully) or this could be the first sign the MAF is on the way out.

Not the bloody turbo again!!

I tried getting a maf off ebay, I made sure it was the same part no. but when i tried it out i seemed to loose all the boost. I'll get some contact cleaner to clean my original one out first before taking the plunge again.

I found a cam belt change quietened mine a little. Also a good service (all fluids and filters) helped too. You might want to try fitting the Seat soundproofing mod. For £35 it does take the edge off the injectors a little.

Aside from this, mixture problems can cause a diesel to sound rough. Weaker mixtures (knackered MAF causing the ECU to think there's less fuel coming in than there actually is) increases combustion temps and gives more pronounced ignition clatter. Reduced fuel presses ends up meaning the fuel is not atomised as well by the injectors and so can mean a rougher burn.

Try a change of fuel, or throw a can of Millers into the tank to up the cetane rating a little. Should improve the smoothness a bit.

hi mate whats the seat sound proofing mod? does it make it quiter?

Here you go mate:

http://www.briskoda.net/forums/fabia/sound-proofing-mod/29220/

cheers for that mate

Blimey, i never saw that before. I'll definately be getting that.