So this morning started the car as normal engaged reverse and then this loud hoover like noise started when i gave it some revs, this continued until the engine got warm (12 degrees outside) about half way between the 60 and middle on temp gauge.

Spoke to a guy i work with and he said it may be a secondary air intake that heats up the CAT when its cold to help with emissions?

Does the focus have this? googled it and there is a part but ive not been aware of it before now.

Focus 1.8 TDCI

Thanks

Never heard of this before, havent gotten any hoovering sounds during the winters previously.

Nor have I........ this was the first time its ever happend.

I was told that on Skoda's which the fella here has they only make noise when the screws holding it together come apart.

Ive got to get fuel at lunch so will see if it happens again

if you can please try to record it :)

So went out at lunch and...............nothing!

Started and went perfect

confused now lol will see if it happens in the morn.

I was thinking maybe a split pipe but because nothing happen now i just dont know

Happend again today and attention swaying towards a turbo issue, Its more of a woooooooooooo sound like theres a ghost under the bonnet :P, really noticable when idle and in lower range 1000/1500 revs.

if its at idle too then i doubt its turbo related. it will only spool up from 1500 revs onwards

pop the bonnet open on a cold morning and try to get a good listen inside the engine bay to determine which side the noise is coming from