Here are some evident signs that your car’s exhaust manifold may be leaking:
- Unusual Noises
You may hear a ticking or tapping sound that can seem like a strange engine noise. However, it’s likely due to gasses leaking through the exhaust manifold.
These sounds will be more prominent when the engine is cold than when it warms up. This is because a crack in the manifold gets smaller when exhaust gasses heat the metal, expanding it, and the leak gets reduced.
- Exhaust Smell in the Engine Bay
A damaged exhaust manifold or gasket will leak exhaust fumes, leading to an exhaust smell in the engine bay or cabin. These exhaust fumes can be harmful as they contain toxic carbon monoxide. You may also notice a burning smell if the hot exhaust gas burns a plastic part or wire in the engine bay.
- Sluggish Acceleration
A leaky exhaust manifold can negatively affect the removal of exhaust gasses from a cylinder (exhaust gas scavenging), causing a build-up within the engine. This will reduce the combustion efficiency and result in reduced engine performance, evident as sluggish acceleration when you press the accelerator pedal.
- Poor Fuel Efficiency
A cracked exhaust manifold can allow air to enter the exhaust system, affecting the readings of the oxygen sensor (O2 sensor). The oxygen sensor may incorrectly prompt the Engine Control Unit (ECU) to inject more fuel into the engine. This disturbs the air-fuel ratio required for efficient combustion, lowering the vehicle’s fuel efficiency.
- Illuminated Check Engine Light
The ECU activates the Check Engine Light (CEL) if the oxygen sensor’s output is beyond the expected range. If the exhaust leak is large and the ECU injects way more fuel than required, engine misfires can occur, triggering the CEL and registering a fault code.
Can You Drive with an Exhaust Manifold Leak?
You shouldn’t drive your vehicle with an exhaust manifold leak since harmful gasses such as carbon monoxide can enter the car’s cabin and make you sick. In fact, high enough concentrations of carbon monoxide can be fatal. The catalytic converter can get damaged due to excessive misfires caused by an exhaust manifold leak. Plus, a leaking manifold can cause a rich condition, resulting in malfunctioning oxygen sensors fouled by fuel.
So, if you suspect an exhaust manifold leak, get your car inspected by a professional soon to ensure your safety and prevent damage to your vehicle.
Nelson Xavier Ssenyange
Team Leader
Germax Autos, Spares & Garage Ltd
Lukade Road, Naalya
0779250886/0752088734
