What are the symptoms of a damaged intake manifold?
2 Answers
Symptoms of a damaged intake manifold: Mainly caused by cracks leading to air leaks, resulting in high idle speed, poor acceleration, stalling during acceleration, and in severe cases of cracking, the engine may not start. Below is more relevant information: 1. How the intake manifold works: For port fuel injection engines or diesel engines, the intake manifold simply distributes clean air to each cylinder's intake port. The intake manifold must distribute the air-fuel mixture or clean air as evenly as possible to each cylinder. To achieve this, the length of the gas flow paths inside the intake manifold should be as equal as possible. To reduce gas flow resistance and improve intake capacity, the inner walls of the intake manifold should be smooth. 2. Consequences of a damaged intake manifold: The intake manifold must distribute the air-fuel mixture or clean air as evenly as possible to each cylinder. To achieve this, the length of the gas flow paths inside the intake manifold should be as equal as possible. To reduce gas flow resistance and improve intake capacity, the inner walls of the intake manifold should be smooth. If the intake manifold is damaged, it will cause air leaks, reduced gas pressure, and weakened intake capacity, leading to decreased engine power. Insufficient air intake can also increase carbon buildup.
I remember driving for over a decade, and recently my intake manifold cracked, causing some really troublesome symptoms. The car often wouldn't start, and when it finally did, it was prone to stalling. At idle, the RPM was unstable, fluctuating wildly, making the steering wheel shake. Acceleration was weak—stepping on the gas pedal felt like stepping on cotton, making overtaking nerve-wracking. Fuel consumption skyrocketed; a full tank that used to last 500 kilometers now ran dry before even 400. The most obvious sign was hearing a hissing sound under the hood on the highway, like a small whistle. At the repair shop, the mechanic said the manifold crack caused a vacuum leak, leading to an overly lean air-fuel mixture and triggering the ECU error light. Delaying repairs would waste fuel and damage the engine, so I quickly replaced the gasket. In short, if you notice unstable idling or unusual noises, don’t delay—avoid getting stranded halfway.
