Skip the auto shop - Our mechanics make house calls
  1. Home
  2. Articles
  3. Symptoms of a Bad or Failing Exhaust Manifold

Symptoms of a Bad or Failing Exhaust Manifold

exhaust manifold

Exhaust manifolds are an engine component that is found on all internal combustion engines. Exhaust manifolds are usually made of cast iron or stamped steel and are designed to collect exhaust gases from the engine cylinders and transport them into the exhaust pipes for expulsion. The exhaust manifold is attached to the engine cylinder heads and has ports that collect exhaust gases from each individual engine cylinder. Cast iron manifolds are usually one piece, while stamped steel ones are usually welded together. Both are designed to withstand the high stress and heat conditions required to trap and transport exhaust gases. While they are heavy duty in nature, they can still be prone to issues, and can cause problems with drivability when they have a problem. Usually a bad or failing exhaust manifold will produce a few symptoms that can alert the driver of a potential issue.

1. Noisy engine exhaust

One of the first symptoms of a problem with the engine exhaust manifold is an excessively loud exhaust. If the exhaust manifold cracks, breaks, or leaks, it can cause an exhaust leak that will lead to a noisy exhaust. The vehicle may produce a hissing or tapping sound from the engine bay that may get louder when the engine is accelerated.

2. Decreased power, acceleration, and fuel efficiency

Engine performance issues are another symptom that can be caused by a problematic exhaust manifold. If the exhaust manifold cracks or leaks, it can cause an exhaust leak that can negatively affect engine performance. An exhaust leak can cause the vehicle to experience a reduction in power, acceleration, and even fuel efficiency.

3. Burning smell from the engine bay

Another symptom of a problem with the exhaust manifold is a burning smell from the engine bay. If the exhaust manifold has any issue with the heat shield or exhaust leaks the excess heat can cause damage to nearby electrical and plastic components. Exhaust manifolds can reach temperatures in excess of nine hundred degrees Fahrenheit which can cause any nearby or contacted components to burn up. Burnt components may produce a plastic burning smell that is sometimes accompanied by smoke and can lead to other issues so any burning smells should be checked out to make sure that they are not a major issue.

While exhaust manifolds are usually built to be heavy duty to enjoy a long service life, they can still be prone to issues simply due to the high stress conditions they are constantly under. If you suspect that your vehicle’s exhaust manifold may be having an issue, have the vehicle inspected by a professional technician, such as one from YourMechanic, to determine if the vehicle will need an exhaust manifold replacement.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
Still not sure about your car's issue?
Diagnose your car
What kind of issue are you experiencing?
Brakes are squeaking
Car is not starting
Car is overheating
Car is shaking (vibrating)
Fluids are leaking
Heating and A/C
Smoke or steam is coming out of the car
Warning light is on
Icon-warranty_badge-02

Skip the repair shop, our top-rated mechanics come to you.

At your home or office

Choose from 600+ repair, maintenance & diagnostic services. Our top-rated mechanics bring all parts & tools to your location.

Fair & transparent pricing

See labor & parts costs upfront, so you can book with confidence.

12-month, 12,000-mile warranty

Our services are backed by a 12-month, 12,000-mile warranty for your peace of mind.

Get A Quote

Need Help With Your Car?

Our certified mobile mechanics make house calls in over 2,000 U.S. cities. Fast, free online quotes for your car repair.

GET A QUOTE

More related articles

Insurance Requirements for Car Registration in Kentucky
The Kentucky Transportation Cabinet requires that all drivers in Kentucky carry liability automotive insurance, or “financial responsibility” in order to operate a vehicle legally and maintain vehicle...
How to Transfer a Car Title in Idaho
In order to prove ownership of a car, you must have the title. However, when a car is sold, given away or inherited, the title needs...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...


Related questions

Q: Engine not running correctly after rebuild

I'd need to know the symptoms you are having but I'm assuming the engine is burning oil. Valve seals control the oil that lubricates the valve stems and prevents it from seeping into the guides in excessive amounts. The piston...

Q: How hard is it to change your muffler

If you see a hole in the muffler then you should have an exhaust shop check the entire exhaust system to see if other leaks are found and what needs to be done to repair the exhaust leaks. The check...

Q: Car chokes, shakes, and shuts down

The symptoms you describe lead me to believe that your Subaru is experiencing electrical issues. It is possible that the computer has a bad connection or that it is possibly starting to fail. To be 100% certain, I would enlist...