Good evening, looking after some opinions or maybe past experiences with similar issue. I have a vacuum leak as I can hear a hissing around the throttle body area, however I tried the soapy water method and I can’t see any bubbles etc, although it might be hard if the leak is underneath (I did use a mirror). Are there any common faults with the body throttle gasket or any ideas what could it be? I don’t think at this stage that there’s a leak from inlet manifold gasket, I can pinpoint the location of the hissing, however whatever I do the hissing is constant and won’t change (moving hoses etc). I have attached an image to show the area where the noise comes from. Is it worth replacing the gasket and go from there? Or can the sound be diffused from somewhere else?
 

Thank you

You won't get bubbles from a vacuum leak. The air is being sucked into, not out of, the break. Don't know how you would easily find such a leak.

7 minutes ago, cliffcoggin said:

You won't get bubbles from a vacuum leak. The air is being sucked into, not out of, the break. Don't know how you would easily find such a leak.

Yes, sorry, you are right, I didn’t mention, I did take the intake air hose out of the throttle body and blew air in whilst sealing the best I could.

Apologies for jumping in, but try squirting Easistart or similar onto any suspect areas/connections and listen for any change in engine note/revs. Obviously start at the lowest point and only treat one area at a time.

Regards,

Gareth. 

1 minute ago, Magnet said:

Apologies for jumping in, but try squirting Easistart or similar onto any suspect areas/connections and listen for any change in engine note/revs. Obviously start at the lowest point and only treat one area at a time.

Regards,

Gareth. 

Thank you Gareth, I did read about this method, being honest, I’m a bit afraid as I have read stories about instances where it caught fire, although I’m seriously thinking to try it. 

Could try WD40 instead, and look for blue smoke from exhaust. 
Regards,

Gareth.