Okay, so I'm still in the middle of nowhere trying to sort out what on earth is causing this siren sound on the passenger side. Seems to be coming from the passenger side turbo/wastegate turbo and is evident on acceleration. Not heavy acceleration though. Gets high pitched during acceleration and is gone when boost kicks in. Sounds like a big air leak. At first, I was thinking the wastegate actuator wasn't doing it's job and just kept leaking air from the actuator. Hence, boost is very much delayed. Changed the actuator but problem's still there. Got a zed mechanic to have a check and he thought it was the BOV's. Took the BOV's out and blocked the airway... still there. Now, I'm in the process of getting new BOV's and see if it'll be the solution. Worst case scenario, passenger side turbo has got a bad shaft play and is causing the blades to hit the housing. To add up, I've tried disconnecting my passenger side O2 sensor (solved the hesitation!) and has been recently blowing some amount of smoke on the passenger side exhaust after boost. Now, questions to our gurus: 1. What are the signs and symptoms of such (shaft play)? 2. It's normal to blow smoke when the O2 sensors are disconnected, isn't it? 3. One of the members mentioned about checking the water level if it needs to be topped up. Noticed that 3 days ago when I went to check. Opened the the radiator cap. Had to top up! Is it related to such? 4. What are the chances that it could only be the buggered BOV's? 5. Has anyone experienced the same problem in the past? Any form of smart diagnosis will be much appreciated as I have been haunted by this problem for some time now! Really want to get this fixed soon... Cheers, Arvin ..... .... ... .. . P.S. Question #6: If you're given a chance... what chance would it be? And why? :rofl: ..... .... ... .. .