Sorry for the slow reply and thank you for yours.

I have checked the 2 90 degree pipes and the ones at the rear near the bulkhead and all look ok and are seated well and tight.

Going to remove the intercooler pipes this afternoon and clean and reseat them to rule them out. Think it must be deeper in the engine bay. Is there anything Else I can look at in the same area? Am I best going in from underneath?
Thanks

Shame it wasn't 1 of the front hoses - at least they don't cost much & aren't too bad to change.
Good look finding the culprit ! Paul,
2001 Discovery 2 TD5, 211,000 miles & climbing
2006 FFRR TDV8 Vogue 145,000 miles & climbing
Member of Midland (Land) Rover Owners Club, www.mroc.co.uk

Might be worth giving the little 90 degree pipes another look, when mine gave up on the 3.6 the damage was obvious on the one that was leaking (it looked like the engine cover had been rubbing on it). I replaced both/all of them (I’m old I can’t remember it it had 2 or 4) but I do remember finding one that looked fine when fitted but was perished badly and had been leaking.

Hi Mark
As you say, it does sound like an air leak in the induction system, up stream of the turbos.
Have you had a 'Engine System Fault' or similar warning on the dash and no throttle response?
I had the above symptoms which proved to being caused by a crack in right hand inlet manifold / valve cover assembly.
I'm on my phone at the moment and I don't know how to post a link on it, but have a look for a thread I started last year about this. In it you will see a photo of the assembly and the crack in it.
Hope this helps
Andy

Morning, thanks for the reply’s il have a search today. I took the car to a specialist yesterday that confirmed it’s a boost leak on the drivers side. Cars booked in for Friday to see what it is. Hopefully something and nothing as it definitely didn’t do it before the alternator was changed. Thanks for all your replies and help, will post the fault as soon as I know.

Regards
Mark

Hi all,
Had the vogue in the specialist today. Still can’t find the cause of the hissing? Has anyone else got any ideas where to start with this?

Thanks