Hey guys my turbo has started making a police siren noise just before boost kicks in and after I lift off and I'm wondering the reason? My car also has blueish smoke coming from the exhaust not constantly but every now and again, wondering if the two issues could be linked? Any help would be appreciated. Thanks

I had this really bad whine/siren noise for a while also except the noise was there during spool and whilst on full boost.

Started out fairly quiet and then gradually got louder as time went on. Turned out I had a leak between the exhaust manifold and the turbo where one of the bolts had lossened off.

I'd go through all possible areas where a boost leak could be to start with. E.g intercooler pipes, BOV. Could be just a simple boost leak.

Oh okay thanks! I just got the car serviced too and they didn't really say anything about the noise so I'll check out the pipes