What are the symptoms of a throttle valve failure in the Geely Emgrand?
3 Answers
Throttle valve failure generally causes the car to fail to start, or after starting, the throttle valve does not return to position when the accelerator is pressed. It may also result in black smoke emission, high fuel consumption, elevated idle speed, and unsteady acceleration. Meaning of the throttle valve: The electronic throttle valve is an important control component of the car engine, consisting of the engine, speed sensor, and throttle valve. The electronic throttle control system allows precise control of the throttle opening, improving fuel economy and reducing emissions, achieving idle speed control, cruise control, and vehicle stability control integration, and simplifying the control system structure. Causes of throttle valve failure: Throttle valve failure is largely caused by carbon deposits inside the throttle valve. The problematic throttle valve often contains black carbon powder resulting from incomplete combustion. Prolonged use of the throttle valve and poor driving habits of the owner are the main causes of carbon deposits.
Last time when I was driving the Emgrand, I encountered a throttle valve malfunction and it was such a nightmare! At idle, the steering wheel shook like crazy, and the tachometer needle was dancing up and down. Accelerating with a deep press on the gas pedal felt extremely sluggish, as if the power was being strangled, making overtaking particularly nerve-wracking. The scariest part was when the car suddenly stalled at a red light, and the honking from the car behind could give you a heart attack. That time, the warning lights lit up like a Christmas tree, and a yellow 'Engine Malfunction' sign popped up on the dashboard. The mechanic said the throttle valve was dirty, affecting the air intake—just like trying to run with a mask on and not being able to breathe. After a thorough cleaning, the fuel consumption also dropped, going from 9 liters per 100 km in the city with AC on back to 7.5. Never delay fixing such issues; severe carbon buildup can even lead to cylinder pressure problems.
My neighbor's Emgrand had serious throttle body issues. Cold starts were a nightmare - it took three or four key turns to fire up. Gear shifts were jerky, especially the violent lurch during 2nd to 3rd gear upshifts. Once on the highway, the RPM fluctuated wildly making cruise control impossible. The shop pulled a P0121 trouble code and their borescope revealed sticky throttle plate movement caked with black sludge-like carbon deposits. After replacing the entire assembly, the mechanic shared a pro tip: add fuel system cleaner every 20,000 km and avoid prolonged low-RPM driving. Now he does regular throttle body cleanings, swearing it's way more cost-effective than replacing oxygen sensors.
