Lexus LS Hybrid Boost Pressure Issue

I'm experiencing a strange issue with my 2018 Lexus LS hybrid. The check engine light comes on, with a significant reduction in engine power and poor engine response. Sometimes, the engine even stalls at idle. Fuel consumption has also increased noticeably. I'm also hearing a distinct whistling noise, and a loud hissing sound when accelerating. The car has 115523 km on the clock. I suspect it might be related to a bad boost pressure system. Any ideas where to start checking? I was thinking of checking the pressure sensor and maybe something with the turbocharger.

4 comment(s)

The symptoms you describe certainly point to a boost pressure issue. The whistling and hissing sounds are strong indicators. Has the throttle body been inspected for leaks or damage? Are you familiar with how boost control systems work? Hybrid cars can have very complex systems.

I've not checked the throttle body specifically, but I'm familiar with the basics of boost control, though hybrid systems are new to me. Could a defect in the wastegate valve cause these issues? Where should I start to look for issues with the wastegate? Where is it typically located on this engine?

A faulty wastegate valve is a highly probable cause, considering all the symptoms you're experiencing. It's responsible for regulating boost pressure. If it's stuck open, you'll experience low boost and reduced power. Considering the complexity of hybrid systems and the potential for misdiagnosis, I would advise taking it to a qualified mechanic to properly diagnose and repair the issue. It could save you time and money in the long run.

I took it to a local shop, and you were spot on. It was indeed a defective wastegate valve. They replaced it, and the car is running perfectly now. The total repair cost came to 860€.

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