Hi Gareth. The clutch master cylinder was changed due to the clutch pedal hitting the floor and not coming up. The master cylinder had a crack in it and was squirting oil. That part of the car seems fine its just the rattling noise when I press the acceleration pedal that concerns me. The mechanic said its nothing to worry about and I have a noisy engine? I've never noticed the noise to be thst loud before? It's more of a rattling noise than anything else. Thanks.