6 Symptoms Of A Clogged Exhaust Manifold (+How To Clean It)

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Okay, so what are the symptoms of a clogged exhaust manifold? When the exhaust manifold gets clogged, you’d notice your car starts making a different unusual sound as you drive. Also, you may notice that the fumes (gaseous releases) from the exhaust pipe are dirtier than usual.

You see, many drivers don’t really pay attention to how their vehicle’s exhaust is performing, and that’s not advisable. The exhaust system is as important as your engine – they actually work hand-in-hand.

If anything should go bad inside your exhaust, your engine would be affected too, That said, it is important to pay attention to failing exhaust components and fix them earlier.

Well, there are other signs of a clogged exhaust manifold, and they’re explained below. We also talked about how to clean a clogged exhaust manifold.

Let’s get started!

What Are The Functions Of Exhaust Manifolds?

Put simply, exhaust manifolds are the first “component” in the exhaust system setup. The exhaust system is designed to collect and dispose of emissions from the engine of an automobile. Typically, a standard exhaust system comprises the following: manifold, cat converter, muffler, and tailpipe.

Some drivers may custom-ly add a resomer to further reduce the noise that comes from the exhaust while driving (especially during acceleration). Hereunder are the common signs you’d likely see, or experience when your exhaust manifold is clogged.

Symptoms of a Clogged Exhaust Manifold

There are a couple of reasons why the manifold could get clogged; this includes gas and diesel turbos. Well, a clogged manifold can be cleaned – the guide provided below.

1. Dirtier, Smelly Exhaust Fumes

If you always pay attention to your exhaust, you’d be able to detect when the fumes coming out of the exhaust tailpipe change in color and “smell.”

A clogged manifold would hold more dirty gases in the chamber, when they accumulate, some of them would find a way to escape, and they’d be very smelly.

Well, a leaky manifold can also change the smell of the fumes that are disposed of from the exhaust pipe. The summary is, a clogged or leaky exhaust manifold will cause you to perceive strong, smelly gas (coming out from the exhaust tailpipe) while you drive.

2. Loss Of Power

While we are aware that there are many things that could lead to engine loss of power, a clogged/blocked manifold is one of the possible causes. As hinted earlier (in this article), the exhaust system is designed to work hand-in-hand with the engine.

Thus, if anything should go wrong in the exhaust system, it can directly affect the engine’s performance. That reinstated, a clogged manifold would prevent harmful gasses – from the engine cylinders – from going out; hence, those gases are sent back into the engine.

With the gases being sent back to the engine, the engine would find it difficult to function efficiently as supposed. This is how a faulty or malfunctioning manifold can cause a loss of engine power.

Related Post: What Are Bad Muffler Symptoms?

3. Unusual Loud (Cranking) Noise When You Rev The Engine

If you rev up your engine and hear a loud unusual noise from the rear, that could be your exhaust – probably the manifold is broken or clogged. A working exhaust manifold contributes to keeping the sound coming out of your car’s exhaust at a minimal level.

Another possible reason why you’re hearing such loud noises when you rev up your car is “loopholes.” Yes, if the manifold has a loophole (leaky spots), sounds waves would escape from those holes before even getting to the muffler, where they are silenced.

So, a faulty exhaust manifold can generally cause loud, cranking noise when you try to accelerate or rev up your engine.

4. Significant Decrease In Fuel Efficiency

Seems like every little issue with your car affects the fuel economy/efficiency? Well, somehow, that’s it – that’s how modern cars are designed. Every component and system used on modern cars are interconnected; hence, when one system fails, it may directly affect many others.

Talking about how a faulty manifold can affect fuel efficiency, here’s how it happens. When the manifold is clogged, emission gasses won’t get out from the exhaust, instead, they are sent back to the engine. This makes the engine work more “harder” than usual.

Now, since the engine is kind of overworking itself, it uses more fuel and also needs more oil to stay clean. Apparently, the “more” fuel intake by the engine would lead to a significant decrease in your car’s fuel efficiency.

5. Burning Smell From The Engine Bay

Yes, when something goes wrong in the exhaust system, harmful gases are sent back into the engine, get excessively heated up, and then released from any open space. Now, due to the excessive “heating up” in the engine bay, these gases would escape with a burning scent.

So, when you start perceiving a burning smell coming from your engine bay, first, check the engine and its surrounding component, if everything seems good, the culprit could be your exhaust manifold.

6. Random Performance Issues

When your car starts slacking in performance, and you’re sure there’s nothing wrong with your engine, directly, that’s a sign that you should check other important parts of your car, and that includes the exhaust.

A loose manifold can actually contribute to different unusual performance issues – especially on newer cars. Your best bet would be to change the manifold (if broken), or fix the manifold gasket (if that’s the culprit). Generally, a good and working manifold has an important role to play in engine performance.

Related Post: Signs of a Clogged Catalytic Converter

How To Clean A Clogged Exhaust Manifold?

If your troubleshooting or inspection showed your manifold is clogged, the next thing to do is to unclog it. Unclogging your car exhaust manifold is quite a technical task, so, it is advisable that you get a mechanic to do that for you. Notwithstanding, here’s how to do it yourself.

Step 1: Locate the manifold

First, find out where the exhaust manifold is installed in your car. It’s usually among the components in the engine bay. You can search your owner’s manual for the exact position of your car’s exhaust manifold.

Step 2: Wear safty gear

Put on safety gear, which includes a nose mask and hand gloves, then carefully remove (unmount) the manifold from its position.

Step 3: Clean the manifold

Clean up the manifold using a lubricating spray solvent, and then clean the interior and exterior parts. Ensure that you remove all the dirt and sediments that clogged the manifold.

Step 4: Install the manifold back

When you’re certain that the manifold is now clean – free from any sort of clog, remount it carefully and close the engine bay. Start your car and check for the previous signs that made you believe your exhaust manifold is clogged.

Final Thoughts

Conclusively, a clogged manifold would contribute to the following signs: loss of power, smelly fumes, burning smell, high fuel usage, and loud noises.

You can actually unclog the engine’s exhaust manifold, but it’s best to have a mechanic do that.