My intermittent boost problem was solved a few months ago with a new Bosch aux. water pump but this week, with no real symptoms, there's no boost at all (fuse #23 for the pump is ok). I replaced the Intake Air Temp Sensor thinking it may have failed but the new unit from MB made no difference. Any ideas? Do the SC clutches fail like this? The car has 84k on the clock.
Thanks for your help!