V70 Diesel Turbo Issue

Sounds like a turbo system issue, possibly a boost leak. Check for cracks or loose connections in the intake hoses. Could also be the turbo actuator. Is the noise constant, or only under load?

Inspected hoses, no damage found. Whistling is always present, louder under load. How did you diagnose your V70? Did you have stalling issues, and how did you resolve them?

Constant whistling is less likely a simple boost leak. My V70 had similar symptoms, I suspected the turbo wastegate. I took it to a workshop. They confirmed a faulty boost pressure actuator, specifically the electrical bypass valve. I'd recommend a professional diagnosis to save time and prevent damage.

Thanks, I'll schedule a mechanic appointment. Seems the electrical bypass valve is the most probable cause. Repair cost was 250€. Hope this is a permanent fix. I'll monitor the turbo system, boost control and turbo actuator more carefully.