So I just bought my first Vectra, a 05 SRI 120. It has until now made a kind of hissing whistle that can be heard as it hits 2000 ish rpm. Anyway as of today it made a kind of jolt while driving then got nosier. It now make a "distant police car sound" when sat still and revving the engine. The aux belt returns to normal speed and the sound continues to wind down so I am pretty sure its noise from the turbo.
On the front near the slam panel is a little Vac Valve and I have removed both these pipes and it still does it. I only have to rev a little to get the noise to start (less than 1500). The harder I rev the longer and louder it is.
I did clean the MAP sensor a few days ago but have no fault indications even now and if I disconnect it I get a fault so it seems ok.
I am not sure if its a blown pipe or a blown turbo but would appreciate any help or suggestions.
I have disconnected the large pipe that connects the inter cooler to the manifold and it has a thin layer of oil on its inner surface but this was there before the incident which made it noisy so not sure if this is normal or maybe relevant.
Please help me :-)