A whooshing noise is coming from the engine bay, i took it to a mechanic who thought it was a hose come of or split but nothing was found so up on the ramp it went and belly pan off and still nothing no soot marks or signs at all,,it's got plenty of boost but now it's started to pump out black smoke out of the exhaust and is shooting up the back of the car So any advice would be great It's a 1.8 tdci

i would say that its a split intercooler hose from the egr valve, the split can be difficult to find and often needs the hose removing before the problem is found.