Help with d40 engine

hey guys,
got a 07 tdiesel st-x and yesterday i popped the hood just to clean etc and found that there was a little oil leak near the throttle body and it had sprayed oil on my fan radiator and underneath the engine conver plus oil running down the pipe that connects into the throttle body... now it isnt a massive leak it was just hanging off the bottom nut on the throttle body ready to drip down again...i have noticed i lost a little bit of power and also hearing a winding noise now when i rev up( like old school police ambo siren ) i am just wondering i am away at the moment and have booked it in to nissan on sat anybody got any ideas of what it could be.. i ended up gettin some hose wrap heat stuff and wrapped up the pipe and little bit round the throttle body have noticed a reduction so should i just nurse it back down the freeway to get it fixed, the closest nissan i am at said they cant get me in till next week but i need this fixed as i am scared something might go boom!!!

I would not drive it myself until I found where or why it was leaking.
Any point to letting a good mech have a look at it just quickly until you can get to Nissan???l

I wouldn't panic just yet, it may just be oil carried though the PCV system leaking out around the inlet hose clamp, these engines have alot of blow-by that pretty much coats the entire induction system with oil. Hence why a catch can is a recommended mod.

As for the "winding noise" It could be anything from the alternator, water pump, power steering, turbo, etc etc and possibly not related to the oil leak.

^ What he said about the PCV.

Sure the other noise isn't a boost leak.

Sounds like a split vacuum line
Would explain the drop in power and also the oil leak
Now am only going by what I have heard others have issue with on here as I dont have an oiler but from your description a split vacuum line would fit the bill

It's a boost leak. The oil is from your PCV (blow-by dragging along some oil vapour).

Take the large hose off the side of the throttle body, examine it - there's either a crack or a pinch in it. Either replace the hose or reclamp it so that it sits properly.

Do NOT overtighten the clamp which will cause the rubber to 'pinch' and create a gap. The pressures in there are up to about 24psi so the hose clamp needs to be on firmly, but not to the point of damaging the hose.

It won't cause anything to go boom - it'll just lose boost = loss of power.

Only 1 thread needed.