I was out in my mates 4x4 sapphire cosworth earlier tonight, when accelerating not at full boost, the turbo will suddenly start chattering and the boost gauge needle fluctuates. If you try and drive at 60mph in 5th on light throttle it also does this.

any idea what it could be??

the car is running stage 3 @24psi, the turbo is T3 is i think the bearings have gone as screams over 15psi!!!

i have tried disconnecting the amal valve but makes no difference.




John.