Can an Exhaust Manifold Leak Ruin Your BMW Completely?

There may come a time when your BMW is faced with an exhaust manifold leak problem. It can lead to more damage if not detected and fixed on time. This is why it is important to understand the function of the exhaust manifold system and know the signs to watch out for.

The exhaust system of your BMW functions to cool and purify harmful gases that come out of the combustion system. It expels the treated gases away from the vehicle. However, a leaking exhaust system will cause the fumes to be drawn back into the vehicle instead of outside. This will lead to substantial damage.

Causes of an Exhaust Manifold Leak

The following are some of the most common causes of an exhaust manifold leak:

• Damaged Mounting Bolts: Exhaust manifolds are usually mounted using mounting bolts or studs. These bolts may snap and become damaged causing fractures in the exhaust manifold.
• Blown Exhaust Manifold Gasket: The exhaust manifold gasket may break, which would cause leakage in the exhaust manifold.
• Cracks in the Manifold: The exhaust manifolds are usually made of cast iron because cast iron is perfect for objects that continually undergo thermal expansion. However, the cast iron may crack over time, causing an exhaust leak. Also, there may be fractures in the flanges or they may separate, especially at the weld connections.

Symptoms of an Exhaust Manifold Leak

The following symptoms indicate that there is an exhaust leak in your BMW:

• Burning Smells: If you notice a choking smell of burning rubber or plastic when you lift up your hood after driving, this could be an indication that the exhaust manifold of your BMW is overheating and subsequently burned. Since a damaged manifold cannot transfer heat as they are meant to, it would result in a damaged gasket and exhaust leaks.
• Performance Problems: An exhaust manifold leak can be evident by a slow or sudden loss of power in your BMW when you are accelerating. You may notice that your BMW is unable to accelerate on demand, or you may even need to press the pedal harder to enter the next gear. A loose manifold will gradually reduce acceleration power, whereas a crack or sudden damage will result in an equally abrupt loss of power.
• High Fuel Use: If you notice that you are stopping for gas more often than you used to, it could be an indication of an exhaust manifold leak. A damaged manifold will reduce the fuel efficiency due to low pressure.
• Loud Exhaust Noise: If there is a leak or missing gasket in any component of the exhaust system, the car will begin to make loud noises because of escaping pressure. The noise may be a tapping or hissing sound, a loud grinding, or a rock tumbling The noise tells you that there is improper compression in the engine of your BMW.
• Visible Damage: It is possible to see manifold damage by a simple visual inspection. A damaged manifold will have a visible crack in the metal. Sometimes, there might be a thin hairline crack around the part where it is pressed against the engine.
• Failed Emission Test: When your BMW fails an emission test, it could be a result of an exhaust manifold leak. A leaking manifold lets oxygen into the exhaust stream, and this will cause an incorrect fuel mixture and more emissions.
• Check Engine Light: A leaking exhaust manifold causes your BMW oxygen sensors to believe that there is a lean operating condition existing in the engine’s air/fuel mixture (i.e. insufficient fuel). This will cause the check engine light to come on.

Nikolas Motorsport Fixes Exhaust Manifold Leaks!

If you notice any of the above symptoms in your BMW, you need to bring your car to our professional mechanics! Some of these symptoms may be the sign of another problem in your BMW, so our mechanics will run a diagnostic test and determine the exact source of the problem and notify you.

At Nikolas Motorsport, we are experts in diagnosing and repairing exhaust manifold problems in BMWs. We are conveniently located in Pontiac, MI and we serve car owners in Pontiac, Troy, Royal Oak, Rochester Hills, Farmington Hills, and Bloomfield Hills, MI.

We are staffed with highly-trained, ASE-certified mechanics with experience in providing a variety of service and repair work to BMW, Porsche, and Mini Cooper vehicles. We look forward to helping you with all of your automobile needs!