What does an exhaust manifold do?

The exhaust manifold is the first part of your vehicle’s exhaust system. It is bolted directly onto your car’s engine and collects your engine’s emissions. The exhaust manifold receives the air/fuel mixture from the multiple cylinders (either four, six or eight) in your vehicle’s engine and funnels them all into one pipe.

The exhaust manifold then completely burns any unused or incomplete burnt gases at a very high temperature. Finally once all the gases are in one place and completely burnt, the manifold sends the emissions into the rest of the exhaust system to eventually be expelled.

The exhaust manifold also performs another very important role. It houses an oxygen sensor which inspects the amount of oxygen entering the system. This data is then sent to the fuel injection system where the amount of oxygen used in the fuel/air mixture can increase or decrease.

Smart

Smart is a German automotive brand, established 25 years ago in 1994.

The company is a division of the automotive corporation Daimler AG and operated under the ownership of Mercedes-Benz.

How popular is Smart in the United Kingdom?

Smart isnt’ the most popular brand in the UK, most likely due to appealing primarily to parking-challenged city-dwellers; there are only 96k of their vehicles on the roads of the UK today.

Showing steady growth, however, since their introduction to the UK market in 2003, the trend would suggest that we’re likely to see more of these eccentric looking tiny cars as time goes by.

Smart: Quirky little microcars and subcompacts

Owned by Mercedes-Benz, Smart cars fit into the market you’d expect on first glance. They’re a fun and funky little city car; they’re solid, middle of the road machines, designed to be as versatile as they look.

A Smart car will never fool anyone that it’s a hi-end, luxury vehicle. There’s plenty of glossy plastic and groovy fabrics, yet in the cockpit, you’ll find up-to-the-minute touchscreen media options at the controls. They do come at an inflated price for the small city car market, but by nature of their unique design—there’s nothing quite like them.

Smart cars are cheap to run—but not so cheap to buy

Your Smart ForFour will be more expensive by comparison than its rivals: the Fiat 500, Skoda Citigo, Kia Picanto or Hyundai i10—yet it’s rather hard to pitch the Fortwo against anything because there isn’t anything on the market quite so small. Only the Renault Twizy comes to mind, and that’s barely a car at all.

Once you’ve got one though, your Smart car will cost next to nothing to run with their tiny wheels and low weight. The electric models perform even better with a fuel equivalent of 87mpg.

How often should an exhaust manifold need replacing?

Due to the extreme temperature fluctuations inside the engine, the exhaust manifold is especially prone to wear, however it shouldn’t need to be replaced too often. We recommend having your entire exhaust system inspected every two to three years. If the manifold appears to be worn or damaged in any way, it should be replaced to ensure safe driving conditions.

Always look out for the above symptoms of a failing exhaust system, to ensure you get it fixed early and avoid any further, costly repairs.

What happens during an exhaust manifold replacement?

Our certified mechanics will:

• Inspect the exhaust manifold.

• If the exhaust manifold is visibly damaged or cracked, it will be replaced.

• If necessary, they may also replace the exhaust gasket and clean the exhaust ports. The manifold's mounting bolts may also need to be replaced.

• Advise if other related components need to be replaced.

• They will then check for any leaks around the manifold and test drive the car.

What causes an exhaust manifold to break?

The exhaust manifold is exposed to extreme temperatures – it is constantly heating and cooling, which causes constant expansion and contraction. Despite being made of cast iron or stamped steel, over time manifolds can crack due to the stress from constant, extreme temperature changes.

When should an exhaust manifold be replaced?

Due to the extreme temperature fluctuations inside the engine, the exhaust manifold is especially prone to wear, however it shouldn’t need to be replaced too often. We recommend having your entire exhaust system inspected every two to three years. If the manifold appears to be worn or damaged in any way, it should be replaced to ensure safe driving conditions.

What are the symptoms of a bad exhaust manifold?

Usually, there a few signs you can look for:

• A noisy engine exhaust

• Burning smell coming from the engine

• Decreased power, acceleration, and fuel efficiency

• If the engine warning light comes on

• When the engine makes more noise than usual

How often should you replace your exhaust manifold?

We recommend having your entire exhaust system inspected every two to three years. If the manifold appears to be worn or damaged in any way, it should be replaced to ensure safe driving conditions. Always look out for the above warning signs of a failing exhaust system, to ensure you get it fixed early and avoid any further, pricey repairs.

What happens during an exhaust manifold replacement?

Our certified mechanics will:

• Inspect the exhaust manifold.

• If the exhaust manifold is visibly damaged or cracked, it will be replaced.

• If necessary, they may also replace the exhaust gasket and clean the exhaust ports. The manifold's mounting bolts may also need to be replaced.

• Advise if other related components need to be replaced.

• They will then check for any leaks around the manifold and test drive the car.

What is the average life of an exhaust manifold?

The lifespan of an exhaust manifold depends on the car, the driver and how often the car is used. In general, an exhaust manifold should last at least three years, but we recommend having your entire exhaust system inspected every two to three years. If the manifold appears to be worn or damaged in any way, it should be replaced to ensure safe driving conditions.

Can you drive with a broken exhaust manifold?

While you can technically drive with a broken exhaust manifold, it's neither safe nor legal and poses a number of issues when you're out on the road. Your exhaust plays a vital role in the healthy running of your car, therefore when the exhaust system experiences issues, it should be inspected as soon as possible.

Do exhaust manifolds deteriorate with age?

Yes exhaust manifolds are prone to wear and deterioration over time as they are constantly exposed to extreme temperatures. Despite being made of cast iron or stamped steel, over time manifolds can crack due to the stress from these constant, extreme temperature changes.

The law, vehicle regulations and your MOT

There are strict regulations regarding exhaust systems and car emissions. A car's exhaust system, including the manifold, cannot have any serious leaks, corrosion or cracks. An annual MOT tests both the exhaust system for leaks and deterioration and the emissions coming from the exhaust system.