Vauxhall Astra sucking/howling engine noise

its not uncommon for the turbo impellor bearing to fail on that engine causing the turbo to make a loud howling noise,check the turbo and intercooler intake pipes are not damaged or loose,what work did you have done on turbo?check all vacuum pipes are onto actuators ok

thanks for the possible solution, the turbo made a whisltling noise on accelleration from new in march. we found a oil leak under the turbo in sept. vehicle retuned mid sept for oil leak & we questioned dealer should the car whistle .they changed a gasket on the turbo ? .whistle noise gone, first noticed intermitant sucking /howling start of nov aprox, looking around engine bay in dec noticed oil lesk again on the turbo, 17 jan dealer repaired 2nd oil leak on turbo (gasket) but the intermitant noise is still present .