XC60 Diesel Intake Manifold Flap Issue

I encountered nearly identical symptoms in my previous 2016 Audi A4 diesel. The hissing sound, reduced power, and rough running are strong indicators of an air intake or manifold issue. The intake manifold flap control regulates the amount of air entering the engine at different speeds. When defective, it can create a lean or rich fuel mixture, resulting in the observed symptoms. Did you check for any engine error codes related to intake manifold or air intake?

I did retrieve a diagnostic trouble code (DTC) pertaining to the intake manifold flap control. When you mention air intake, are you referring to a fault in the mass airflow (MAF) sensor, or are there other potential components that could contribute to this issue in conjunction with the manifold flap control, such as hoses or vacuum lines?

In my case, the error code pointed directly to the intake manifold flap motor. While a faulty MAF sensor could, in theory, influence engine performance, the hissing sound and the specific error code strongly suggest the intake manifold flap control as the primary suspect. Given the described symptoms and error code, I suggest consulting with a qualified Volvo technician for a definitive diagnosis and repair. Continuing to operate the vehicle in this condition could potentially lead to further engine damage.

I took the vehicle to a certified Volvo workshop. As suspected, the switch intake manifold control was defective, and I authorized the replacement at a cost of 465€. Thanks for sharing your experience and insight.