Lexus RC Whistling Hissing Noise

Okay, Lexus RC aficionados, I'm in a bit of a pickle with my 2021 RC hybrid. It's got 121294 km on the clock, and I'm experiencing what I suspect is a boost pressure actuator fault. The check engine light is mocking me daily. Performance is suffering – reduced engine power and seriously poor engine response. But here's the kicker: there's a whistling noise, almost like a tea kettle, and a LOUD hissing sound under acceleration. Sometimes, it even stalls at idle, which is terrifying at junctions. Fuel consumption has also mysteriously skyrocketed. I suspect a defective electrical bypass valve, possibly in the turbo wastegate system. Anyone else encountered anything like this? I've checked the obvious pressure sensor connections, but I haven't dug too deep into the turbo system itself yet. Any thoughts before I start tearing things apart?

4 comment(s)

Sounds familiar. I've got an RC too, and I had similar symptoms. Whistling, then the hissing... power loss was gradual at first, then BAM. Check your turbo actuator.

Thanks! When you say 'check the turbo actuator,' what exactly did you do? Did you replace it yourself, or did you just confirm it was the problem before taking it to a workshop? I'm comfortable with a wrench, but turbos make me nervous.

Nah, I'm not that brave. Just pointed the mechanic in that direction. Turned out to be the culprit. New actuator and I was good to go.

Alright, that's the confirmation I needed. Sounds like a workshop visit is unavoidable. Thanks for the insight! I'll let you know what happens. It turned out it was indeed the electrical bypass valve, and the total repair was around 250€. Really appreciate your advice!

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