Whilst out today going to Darlington on the A68 I was going uphill into Toft hill in top gear going about 50 mph at 2,000 revs. Started to lose speed and power, revs dropped to about 1,200 and speed to about 30, dropped into 4th put foot to floor revs went up and at 1,500 ish I heard a noise that siunded like a very noisey hoover, revs went up to about 3,000, speed picked up to about 40ish. Foot stayed on the floor, revs and speed stayed constant. Once I got to the top of the hill I dropped the revs to below 1,500. noise went. For the rest of the trip when accelerating hard above 1,500-2,000 revs the noise came back, once the speed picked up and stayed constant and the accelerator was eased off the noise eased off. Could the noise thats sounds like forced air be a sign of damage to the turbo or to a pipe from the turbo. I've checked the pipes dosn't seem to be any losse but could there be a hole in one. Has anyone with a bit more experience give me an idea of the problem. By the way I have a TD4, regulary serviced, in fact due to be next month.

I could pop round tomorrow mate.

Sounds like split in a hose down stream of the turbo. Was there any black smoke when it was making the noise?

I agree - absolutely typical symptoms of a turbo hose failure.

Split only opens up under pressure - usually above 2250 - 2500 rpm.

A cheap easy fix if this is confirmed.

happened on my Di,
intercooler to inlet manifold detached from intercooler but air only blew out at over 2000rpm, hard to find it.
get a friend to rev the motor up while you look for the fault under the bonnet

Split in the intercooler to inlet manifold pipe, what a s*d of job getting the bottom clip off back on again.

Hi , barry invest in a full set of silicone hoses

Small open ended spanner on the hose clip nut makes it easier, or cut the clip off.
Usual place for the hose to split as it rubs on the metal clip/bracket, make sure you position the hose away from the clip/bracket or use a piece of the old hose to protect it.