406oc.co.uk

My motor goes really well: 406 est 98000 miles 2. HDI
it might be my ears but I think it's developed a sort of hissing sound when foot to the floor and revs mid range. Nothing on general motoring and nothing at lower revs. No discernable smoke from the exhaust.
Is it anything to worry about?

check all your boost hoses not sure if yours is 2.0 or 2.2? if 2.2 then check the top S shaped one mine split at the back off it out off sight but could hear it a blowing a gale at full boost.

If you still got brakes then might not be a vacuum pipe off but have a squiz at them just in case.

It's the 2.0.

Cool less pipe work to look at. I think at idle there should be enough pressure to feel a split blowing just keep out off the way off the fan and other spinning bits.

If you want to look for boost leaks on the bigger turbo pipes, use a white rag to wipe them over as there could be wet oil residue at the point of the leak....