Range rover passing air where manifold meets Block

My rangie is passing air wen driving, it sounds like the manifold gasket to the main block. However...its in the garage at the mo and they have just called me asking if im losing water or over heating which im def not. dont know if they trying a fast one? i.e head gasket or its genuine? Can anyone help? If so whats the costings here typically? Thanks

Hi
When you say it’s passing air, what exactly do you mean?. Is there a loss of power does the engine miss fire, and which engine or what vehicle

Hi there, when i start it up there is like a puffing noise and the more revs i give it the louder and faster it sounds. Its a 4.0 se 98plate. Ive hed a garage look at it today, its not the manifold gasket and the manifold is fine it dose not backfire but has a slight loss of power, the garage have just held their hands up and said they dont know. I dont know what to do next? It sounds like a simple noise to fix but the garage have now said they dont know take it to land rover or something.
Please help

Did they check the head gaskets, the sound you describing is very similar to a head gasket blow , the pressure from this type of blow would sound similar to that of a stem train starting off

its exactly that sound yes, sounds expensive? What parts do i need as i see a few ppl selling complete head gasket sets on ebay for not all that much. But i guess it will come down to labour from the garage? How many hours should it take?

If they start the job first thing in the morning a day or less

cheers