jipninty

take the pipe going to inlel manifold and look for oil, a small amount is ok, if it is dripping wet this could indicate turbo seals

had the same problem it turned out to be a small vaccum pipe in the engine managment box. its behind the speedo

i dont want to be funny but check your oil level. light comes on and buzzer sounds when oil low could be answer to turbo problem also. If you have driven like this for a long time you may have junked your engine . sorry if you have

its porberly from crank case breather pipe above oil filter dont over tighten it will brake and get worse

chain

same trouble here

The best way to get to the horn is to remove the front bumper three torx screws in the wheel arches two more under number plate