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What are the symptoms of an intake manifold air leak?

4 Answers
VonJosie
07/25/25 1:38pm
When there is an air leak in the car's intake manifold, the following symptoms may occur: 1. The engine runs weak. An air leak in the intake manifold causes air to be drawn into the engine through the crack without passing through the air flow sensor. This unmeasured air dilutes the combustible mixture in the engine cylinders, resulting in weak engine performance. 2. Increased nitrogen oxide emissions in the exhaust. Nitrogen oxides in vehicle exhaust are formed in high-temperature, oxygen-rich environments, and an overly lean combustible mixture promotes the generation of nitrogen oxides, thereby increasing the emission of vehicle exhaust pollutants. Additional information: 1. Normally, a car with an intake manifold air leak can still be driven, but it may draw external dust, sand, and other impurities into the cylinders, leading to severe cylinder wear. The engine's intake system consists of an air filter, intake manifold, and air flow meter. 2. Its main function is to provide the engine with clean, dry, sufficient, and stable air to meet the engine's needs, while preventing airborne impurities and particulate dust from entering the engine combustion chamber and causing engine wear.
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DeJake
08/11/25 2:20pm
I've been driving for over a decade and encountered intake pipe leaks twice. The symptoms are obvious: unstable engine idle, the car shakes like sitting in a massage chair with fluctuating RPM; when accelerating, throttle response is sluggish with power loss, especially dangerous during highway overtaking. Fuel consumption suddenly spikes - previously a full tank could run 500km, but drops to around 450km after the leak, wasting money. The check engine light stays on, accompanied by hissing sounds from under the hood like a whistling leak. The root cause is unmetered air disrupting combustion balance, potentially damaging pistons or sensors over time. I immediately took it to the shop - replacing a hose fixed it. Advice: watch for these signals - shaking, poor acceleration, noise, warning lights, high fuel consumption. Early inspection brings peace of mind, don't wait for major problems.
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SanAlessandra
09/27/25 7:54am
As a mechanical enthusiast, I often tinker with engines. The main symptoms of an intake pipe air leak include significant idle fluctuations, unstable RPM, and even engine stalling; a feeling of sluggishness during acceleration with slow throttle response, as the leak disrupts the air-fuel ratio. Fuel consumption increases noticeably, potentially by 10%-20%; sometimes the check engine light comes on when the engine computer detects intake-related error codes. There may also be a hissing noise, especially audible near the leak point. The root issue lies in unfiltered air entering, causing a lean air-fuel mixture, incomplete combustion, and even affecting the exhaust emission system. The solution is to check for aged or damaged pipe connections or hoses—I personally use a spray test to locate bubbling spots, then replace or seal them. Regular maintenance can prevent these issues and extend engine life.
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LeJude
11/11/25 3:05am
I prioritize safety when driving. An intake pipe leak can cause abnormal engine operation: severe vibrations at idle, which can be distracting; and lack of power during acceleration, increasing risks especially on curves or uphill. The check engine light is the most direct warning, often accompanied by a hissing noise. If left unaddressed, it may lead to engine overheating or severe damage, making a roadside breakdown highly dangerous. Increased fuel consumption also adds extra costs. I would immediately pull over to inspect and seek professional repair to ensure my family's safe travels—never cutting corners on safety.
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