i have a 2wd saff and its stage 3 (just set up 2 weeks ago)i have 5~40 fully synthetic oil which i now know is wrong and im changing it at the weekend, when the car is fired up on a morning the is a whirr, it is not the diff or gearbox as i have checked them,i am almost certain its the turbo it does it when the boost reads -5 -0 psi then goes off.it only does it a couple of times then is fine.do you think it is the oil? plese help as it is bugging me thanx rs 4 ever

 

I THINK IV FOUND THE PROBLEM the is a hole in the back of the actuator where my turbo heat sheild is loose and has worn through it.my car is whirring all the time now and wont boost above 0psi.need to find a new actuator and hope thats what it is