What are the symptoms of a leaking car valve?
2 Answers
The symptoms of a leaking car valve are: 1. The vehicle lacks power when driving; 2. The air-fuel mixture is too rich or too lean, causing incomplete combustion of fuel in the combustion chamber, resulting in increased fuel consumption; 3. The car accelerates slowly; 4. The engine is difficult to start, power decreases, combustion is incomplete, carbon deposits are severe, and it may even cause individual cylinders to stop working. The main causes of valve leakage are: 1. Carbon deposits or burns between the valve and valve seat; 2. Incorrect clearance between the valve and valve guide—if the clearance is too large, the valve wobbles and tilts when closing, leading to poor sealing; if the clearance is too small, the valve sticks in the guide, preventing it from closing properly or at all; 3. Insufficient or broken valve spring tension, preventing the valve from closing or sealing properly; 4. The valve clearance is too small, leaving no room for expansion when the valve stem and other parts heat up, resulting in poor sealing.
I've been driving for over a decade, and once had a really troublesome valve leakage issue. The car was extremely difficult to start, especially on cold mornings—it took several attempts to barely get it going. At idle, the whole vehicle shook violently, even the steering wheel was wobbling. There was no power during acceleration, struggling to climb even small hills, and it couldn't pick up speed on highways. Fuel consumption also skyrocketed from 8 liters to 10 liters, accompanied by a strange odor. Later, the mechanic explained that compression leakage caused incomplete combustion, and if not addressed promptly, it could lead to more severe engine wear. He recommended checking the exhaust more often after warming up the car. This kind of malfunction is common in older vehicles that haven't been maintained for a long time, and cleaning the valve clearance can prevent it.
