Aslan Turbo Boost Leak Symptoms

Hey there. I have an Aslan myself, and your symptoms sound very familiar. That whistling and hissing definitely point towards a boost leak somewhere in the turbo system. A defective electrical bypass valve could cause those symptoms, or it could be a pressure sensor giving bad readings. Have you checked for any loose hoses or connections around the turbo and intercooler? The boost control system on these can be finicky.

Thank you for your insights. I have visually inspected the hoses, but I am not entirely familiar with the components of a turbo system. Could you elaborate on the location of the electrical bypass valve and the pressure sensor you mentioned? Also, how would a defective valve specifically cause these symptoms?

Alright, so the electrical bypass valve, often called the turbo actuator, is usually mounted directly on the turbocharger itself. It controls how much exhaust gas is directed to the turbo, which determines the boost pressure. If it's defective – maybe there's an electrical fault causing it to stay open, or perhaps the valve itself is stuck – the turbo won't be able to generate the correct boost pressure. That would explain the power loss, whistling, and hissing (the sound of air escaping). The pressure sensor monitors the boost pressure, and if it's giving false readings, the engine computer (ECU) will adjust fuel and timing incorrectly, leading to poor performance and potentially stalling. Given your limited experience, I would strongly advise taking your car to a workshop for a professional diagnosis. They can properly test the actuator and sensor to pinpoint the problem.

I appreciate the detailed explanation. I will take your advice and schedule an appointment with a trusted workshop to have the boost pressure actuator and related components thoroughly inspected. After the diagnostic at the shop I was told that the electrical bypass valve was indeed defective and they charged 250€ to repair it. Thank you again for your assistance.