UK Car Repair Questions? Ask a Mechanic for Answers ASAP
Is this the first time you've heard this happen or does it happen alot during start up?
Have you had any recent work carried out the car involving the engine/or belts?
If it sounds like belt squeel - then the best place to start maing checks is the belt condition itself and tension - you need to check this with the engine off - and inspect the belt ribs for cracks.if the belt ribs are cracked then that can account for the squeeling - if the belt feels loose and the tension seems slack..then inspections have to be made not only with the belt but to the belt tensioner too - if you can hardly twist the belt 90degrees with both fingers is good enough indication as to tension - but of course its best to actually hear it as i happens..so when the squeeling starts.pop the bonnet open and listen to see if it is the belt or not..if it then id say its most likely your issue and would generally need replaced - even if its the original belt its might time to get it renewed..and its isnt at all a difficult job..so you would be spending to much to get that done £40 at the max inc the belt id say to be honest..but if the belt is removed then its a good opertunity to ispect the pulleys the belt runs over to ensure those are able to spin easily..just incase one is showing early signs of siezure and allowing the belt to slip and create the noise you hear...,but as above going by description id say the belt on the side is likely your best placeto start or replace even.after checks have been made of course...I do hope this helps
Even though the belt seems new doesnt mean that one of the pulleys the belt runs isnt at fault and causing the belt to slip under certain conditions/rpm or even running out of alignment slightly..thats something that needs to be ruled out or addressed - As far as the turbo goes..normally turbo failures result in power/boost loss - they can also and always usually whine under increased rpm rather than at idle when it isnt spinning as fast..and can depending on the failure allow oil to enter the intake and be burnt off creating blue smoke out the back..if there is an imbalance on the turbine/compressor shaft in the turbo you would hear it more under as i mentioned at increased rpm's..unless with the engine off you can get the intake tube off to feel for any play in the compressor side of the shaft and if excessive thats about the only checks you can make as far as that goes..and the most common turbo failure are a result of lack of oil supply to the turbo core / bad servicing as far oil/filter changes....