Repair Exhaust Manifold Leak: Temporary and Permanent Fixes

If you’re looking for a solution to “how to repair exhaust manifold leak,” you’ve come to the right place. You can fix the problem temporarily using epoxy, replacing the gasket if it’s the one leaking, welding the leaky part, or permanently replacing the damaged manifold.

Repair Exhaust Manifold Leak

Let’s elaborate on these two methods (temporary and permanent) so that you can choose freely which one suits you best. Also, you’ll want to know the symptoms of a leaky manifold; read on!

How To Fix a Leak on the Exhaust Manifold? Two Best Methods

To fix a leak on the exhaust manifold, choose between temporary and permanent fixing. The quick fix includes applying epoxy or welding the leaking manifold and/or replacing a leaky gasket. Installing a new manifold and gasket is the best permanent solution for the problem.

An exhaust manifold leak can cause much damage, depending on the leak location, and result in expensive repairs over time. Some of these issues include burning exhaust valves, disrupting the functions of the EGR valve, affecting the proper functioning of the oxygen sensors, improper fuel trim, and, eventually, catalytic converter failure.

What causes the leaking of the manifold? One notorious cause is a leak in the manifold gasket due to continuous expansion and contraction. Another cause is a crack in the manifold. Loose or broken mounting bolts or studs could also be the reason for a leak in your car’s manifold.

Repairing any leaks on time can save you from encountering several problems. As mentioned, there are two methods to fix a leaking exhaust manifold: temporary and permanent methods. 

Either way, start by checking and identifying the leak for a successful leaking manifold repair. Doing so prevents you from experiencing another leak just after fixing one. Once you’ve done that, you’re ready to start the fixing.

Temporary exhaust repair costs can be high in the long run, especially if it’s not done right. The chances of another leak developing soon are high. Therefore, the best thing is to replace the manifold with a new one and permanently fix the problem.

So, if you’re ready to fix this issue once and for all, here are the steps, but first, gather the following tools:

  • A new manifold and gasket
  • Wrench, ratchet, and a socket set
  • Torque wrench
  • Gloves and shop towels
  • A good-quality penetrating oil
  • A jack and jack stands

Once you have all the tools above, you’ll be ready to repair the manifold leak and resolve the problem for good.

These are the steps:

– Prepare the Vehicle

It would help if you made the vehicle ready, which involves allowing the engine sufficient time to cool off. Next, you’ll need to cut off the power. So, open the bonnet, locate the battery, and, using a wrench, disconnect the negative terminal of the battery.

You must park your car on a flat surface or in a garage if you have one, and set it to the parking brake. Now raise the vehicle using a jack, rest on the jack stands, and move to the next step.

– Identify the Leak

As mentioned, knowing the leak’s location is good before beginning any repairs. Physically examine the engine and the manifold to determine the number of leaks available. Also, look under the hood for any leaking oil into the manifold. The leak could be on the manifold or gasket(s).

Rinse the Clay Pebbles Thoroughly

How to find exhaust manifold leaks? Well, use your household vacuum cleaner. Hook its hose up to the air outlet of the vacuum. Connect the hose to the exhaust pipe using duct tape with your engine off and the exhaust system cooled off. Turn the vacuum on, listen, and feel any air between the manifold, head, or elsewhere.

Another way to check the leak is by using soapy water or dishwashing liquid. Ensure the engine is cold, and then stuff rags in the exhaust pipe. Run the engine at idle and spray the manifold with soapy water. Ensure you do it quickly because it heats up fast. You should easily locate the leak.

– Remove the Nuts

Take off the heat shields or engine cover using a ratchet and sockets to find the nuts holding the manifold. You also may require to disconnect the EGR (dipstick tube) valve’s intake pipe for unrestricted access to the manifold. The manifold is mounted onto the engine head using two large nuts.

Apply the penetrating oil and allow the nuts and bolts to soak for 10-15 minutes to facilitate easy removal. After that, unfasten and remove them using a wrench. Please do it gently to avoid damaging the bolt heads. If they feel too tight, apply the oil and give them more time to soak.

– Replace the Manifold And/or Gaskets

Once you’ve removed the bolts, pull the manifold away from its housing. Don’t remove the manifold from the engine head if the gasket leaks. Just pull it enough to allow you space to slide the old gasket out and push the new one into the slot in the cylinder head.

However, if you must replace the manifold and gaskets, obliterate the old materials. Attach your new gasket to the studs on the cylinder head. You also need to attach another between the bottom of the manifold and the exhaust pipes.

Attach your new manifold to the exhaust pipes below the car and slide it into the cylinder head studs. Put the nuts back onto the studs, tighten them with your fingers, and then use the torque wrench to tighten them completely. Ensure you tighten the nuts in the correct order as the vehicle manufacturer recommends.

You should also refill the radiator with the correct coolant if you have removed the coolant lines. Reattach everything back on, including the battery terminal, and move to the final step.

– Test Your Car

A test-start will help you know if everything is working all right. If the engine warning light was on, follow your car’s manufacturer’s recommended steps to clear the error code first. Once you’ve removed the error codes, start the engine with the bonnet door up and listen to any sounds of a manifold leak. It would be best to observe any error codes or warning lights that appear after starting the engine.

Test Start Will Help You Know if Everything is Working

Additionally, look for leaks from the exhaust manifold, cylinder head, or even the pipes below. If you can’t identify any issues, close the hood and road-test your vehicle. Ensure the radio is off to listen keenly to any noise the engine might make while on the road. If you can’t hear noise or see any sign of a leaking manifold, you’re all set, and the problem is resolved permanently!

How to Temporarily Repair the Exhaust Manifold Problem? 3 Best Methods

You can temporarily repair the exhaust manifold problem by using epoxy, replacing the exhaust manifold, or welding the leaky manifold. All three of these methods are not only quick, but they are also very cost-effective. However, the only downside is the absence of mental satisfaction.

Please remember the exhaust manifold can get red-hot therefore allow the engine enough time to cool down before examining the manifold for leaks. It will also help if you wear a good pair of safety gloves if you don’t have enough time to let the car cool off.

What’s the temporary fix for exhaust manifold? There are several ways of temporarily repairing your leaking manifold, including:

– Use an Epoxy

Using an epoxy, such as JB Weld, you can temporarily quickly patch up a small crack or hole on your leaky exhaust. These two make great adhesives. However, before applying the sealant, you must access the manifold to clean any loose rust. 

You can glue something metallic like a coin on the hole to make the high-heat JB Weld more effective. Allow it to cure fully before starting the engine.

– Replace the Exhaust Manifold Gasket

Sometimes the leak may come from the gasket, not the exhaust itself. In that case, the best temporary fix for a gasket leak is a replacement with a new one.

You’ll have to remove the manifold first. You may also use RTV to fix the issue.

– Weld the Leaky Manifold

Exhaust manifolds are generally made of cast iron or stainless steel, and it’s easy to weld these metals and fix any leaks. However, cast iron requires a specific welding process to heat the whole manifold.

Exhaust Manifolds Are Generally Made of Cast Iron

That means you must remove the manifold from the car to weld the crack or hole effectively.

How To Know if a Car Has an Exhaust Manifold Leak?

To know if a car has an exhaust manifold leak, pay attention to the tell-tale signs, including vibration sensations and engine noise. Compromised fuel economy, exhaust fumes in the cabin, poor acceleration, and visible black soot around the manifold and downpipe connection are other surefire signs of a leaking exhaust.

– Vibration Sensations and Engine Noise

You may notice a vibration sensation on the steering wheel. You can also feel it when you step on the pedal, particularly when accelerating. The force of the gasses created from the exhaust pipe will cause your car to vibrate.

Another indicator of a leaky or damaged exhaust manifold is a weird noise from the engine. Your engine will start sounding louder than usual as gasses escape. An exhaust leak will sometimes produce a tapping or ticking sound immediately after turning on the engine and then stop until the next time you turn on the car. 

The noise’s pitch will depend on the leak’s location. Sometimes you can hear a manifold leak sound when accelerating.

– Compromised Fuel Efficiency

An exhaust leak will also ruin your fuel economy. Your car’s electronic control unit (ECU) collects air/fuel ratio readings from the oxygen sensors in the exhaust pipe – the one before and after the catalytic converter.

A leak will make the sensors feed the ECU with incorrect information (the engine is running lean), which will compensate by increasing fuel. You can’t tolerate increased gas mileage; fix the problem immediately.

– Exhaust Smells

If exhaust smells can enter the cabin, you probably have a leaking exhaust. Taking your car to a mechanic or resolving the problem yourself is essential.

Driving with exhaust manifold leak is dangerous. Those fumes are toxic, and inhaling them can cause severe health issues.

– Poor Acceleration

A manifold leak can also make it difficult to accelerate your car. Although it may be a subtle change initially, the problem will worsen, making your driving experience unbearable and more dangerous.

– Engine Check Light

The oxygen sensors will likely register errors and turn on the warning light. Monitor your dashboard to know when something is wrong with your exhaust manifold.

– Black Soot

If you notice any of the signs above, visually inspect your car and see if you’ll find a black soot around the manifold and downpipe connection.

Soot is a surefire sign that you leak somewhere along the exhaust.

Can a Temporary Fix for an Exhaust Manifold Leak Cause White Smoke from the Exhaust?

A temporary fix for an exhaust manifold leak can potentially lead to white smoke from the exhaust. The keyword “white smoke from exhaust causes and solutions” highlights that this issue can occur due to coolant leaking into the exhaust system. This can happen if a quick fix, such as using sealants or adhesive tapes, is employed. To permanently address this problem, it is important to repair or replace the faulty manifold and ensure proper sealing to prevent further coolant leaks.


We’ve discussed two methods to repair exhaust manifold leaks, namely, temporary and permanent.

Here’s a recap:

  • Always start by examining a leak problem to identify the number of leaks and location
  • Various temporary methods of repairing a leaking include epoxy, gasket replacement, and welding.
  • Replacing the manifold and/or gasket is the best way to fix a leak permanently
  • Symptoms of a leaking manifold include a noisy engine, vibration sensations, and compromised fuel economy.

Hopefully, our article has informed you enough, and we are now confident that you are now ready to execute the repair. If so, pick up the tools and get it done!

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