Hi guys I have a 2005 blob with a cosworth panel filter and turbo back exhaust with decat downpipe, I've noticed a bad hissing noise when giving it some usually over 4k revs,I had the downpipe refitted but still the problem persists, I've had it too a few local garage's but there clueless,and I am definitely not mechanically minded,does anyone have any ideas or live locally to me(west Cumbria) or know of any garage's nearby that may have a clue,I can't see any obvious pipes loose or pinched around the throttle body or intercooler but doesn't mean there not! I  have a YouTube clip that sounds very similar to my problem

 Any help would be much appreciated.

11 hours ago, neilt1978 said:

Hi guys I have a 2005 blob with a cosworth panel filter and turbo back exhaust with decat downpipe, I've noticed a bad hissing noise when giving it some usually over 4k revs,I had the downpipe refitted but still the problem persists, I've had it too a few local garage's but there clueless,and I am definitely not mechanically minded,does anyone have any ideas or live locally to me(west Cumbria) or know of any garage's nearby that may have a clue,I can't see any obvious pipes loose or pinched around the throttle body or intercooler but doesn't mean there not! I  have a YouTube clip that sounds very similar to my problem

 Any help would be much appreciated.

Have you done a boost leak test?

No not yet ,I don't think the anywhere near me capable of doing one

Has it got a boost gauge fitted?

Loud pipes save lives

If you dont have boost gauge you could always get a cheap OBD bluetooth dongle and get a boost reading. Only around 15 quid off Amazon. I guess Mattie wants to know if you have a gauge fitted that is leaking.

As above ,definitely sounds like a boost or vacuum leak. Have a visual check of the small vacuum lines for cracks ,splits and see if there's anything not connected. 

If your running the standard top mount intercooler there's not much to leak tbh ,so try checking that there's no pipes split or loose from the turbo (y pipe) or between tmic and throttle body .also if you have a aftermarket dump valve check it's not stuck or leaking 

No I don't have a boost gauge but I may try a Bluetooth one, it has the standard recirculation valve,I  have looked at the pipes but tbh they look ok (but i don't know what to look for they seem in tact),just very frustrating that Ive no faith in anyone around here to check it out for me and I'm OCD with the noise lol .