How can I mend an exhaust manifold

Guide to sealing the exhaust yourself

Your car makes an unnatural roar, loses power or smells of exhaust fumes in the interior? Then part of the exhaust may have rusted through and is leaking. However, you can often repair the damage yourself. In our guide we explain what parts the exhaust consists of and how you repair exhaust manifolds, exhaust pipes and flexible pipes.

Interesting facts about exhausts in cars

The exhaust is part of the Car exhaust system. This not only has the function of guiding the exhaust gases from the engine, but also cleans the exhaust gases by means of thermal and chemical processes. This reduces the burden on the environment.

The second important function is that Soundproofing. Without an exhaust, every car would be many times louder. In city centers, even without an illegal sports exhaust, there would be a deafening noise level. In order to ensure the cleanliness and noise insulation of modern cars, many individual parts work together in the exhaust.

What parts does a car exhaust contain?

The exhaust in a car consists of many individual parts. With this structure, almost all of them can be changed or sealed individually. The most important Parts of the exhaust system are:

  • Exhaust manifold, often just called manifold
  • Downpipe
  • Flexible pipe
  • Catalyst (today G-Kat)
  • for diesel: diesel particulate filter (DPF) or particulate filter for short
  • Central tube
  • Middle silencer, also middle pot
  • Rear silencer, also muffler
  • Exhaust bracket, rubber bracket
  • Lambda probe
  • End piece, also cover

Meet all individual parts such as the exhaust manifold, flexible pipe, catalytic converter and muffler coordinated functions. If a part such as the manifold leaks, this reduces the effectiveness of the entire exhaust system. Quickly changing worn parts protects against consequential damage.

Wear on the exhaust

The exhaust on the car is subject to slow wear due to the high loads. Driving vibrations and the chemical exposure the material is attacked by soot and exhaust gases. In the long run, exchanging parts and changing fasteners is therefore inevitable.

In addition: steel, light metal and cast iron are subject to the corrosionwhen they come into contact with heat, cold, dirt and moisture. Over the years, the material weakens and becomes prone to damage. The Extreme case are Rust holes for example on the exhaust manifold, which lead to various symptoms.

What are the symptoms of a leaky exhaust?

Most of the signs occur small damage only inconspicuous on and become clearer in the case of major damage. The timely replacement of the broken parts avoids that other components are affected. Common symptoms in the event of damage to the exhaust:

  • Car is noisy
  • Rattling from below, pounding noises
  • Exhaust odor in the interior (if the manifold or flexible pipe is damaged)
  • Exhaust smoke increases
  • Loss of performance

Consequences of a leaky exhaust

When driving with a defective exhaust manifold, center pot or muffler, you risk different things Dangers and Consequences. Replacing defective parts eliminates the problem:

Possibilities to seal the exhaust

There are various options depending on the level of wear and tear. In the case of minor damage, that is Mending a cheap alternative to changing, but lasts mostly not permanent. At some point you will have to replace the defective parts, but you can significantly extend the life of the exhaust. In the case of small parts such as pipe connectors, it is generally recommended to change them.

Options for sealing of the exhaust are:

  • Exhaust bandages (rather provisional solution)
  • Repairing the damage with a suitable compound (exhaust repair paste)

Permanent solutions for exhaust repairs are:

  • welding
  • Replacing the broken parts with new or used ones

Can I weld my exhaust on a car?

welding of the car's exhaust is one permanent repair. A good weld is just as durable as the metal itself. However, welding the exhaust continues Expertise ahead and is not work for laypeople. Specialized welding specialists can even repair rear silencers. They also assess whether welding is worthwhile or whether it is more appropriate to swap. Changing parts on the car is always the long-term solution, but welded exhaust parts often last as long as they do after being replaced.

How can I seal my exhaust myself?

If your car Signs of a leaking exhaust shows you can do the damage fix it yourself and seal or change the parts. In the following sections we will show you how to seal the exhaust pipes and exhaust manifolds instead of swapping the parts.

To seal the exhaust using our step-by-step instructions, you will need the following, depending on the location and size of the damage Tools and aids:

  • Lift or pit
  • Exhaust repair paste
  • High temperature silicone
  • Wire brushes
  • Sealing compound
  • Drill including drill and grinding attachment
  • Sandpaper
  • Modeling clay
  • Exhaust bandages
  • Cloths
  • Optional: seals to change
  • Optional: Complete set for exhaust sealing including accessories

Seal the exhaust pipe on the exhaust

1. Preparation

Regardless of whether you want to carry out a repair or change parts: leave the car for a few minutes cooling down. The whole Exhaust system becomes hot while driving. Raise the car or drive into a pit for access to the components in question. Make a note of that Starting position and maybe take a few photos before sealing or changing.

2. Expose the affected areas

Make sure that you have clean access to the damaged area. Whether changing or sealing: You have to reach the affected area from all sides. Solve the Rubber suspension and dismantle any Pipe connector. Is the crack or rust spot in the area of ​​one or more Ring, dismantle You this too.

3. Clean the damaged area

Clean up the area around the damage. This is important so that the repair agent can properly adhere to the surface. Remove coarse dirt and rust with a Wire brush. Then clean the area around the crack with a Rag and make sure that no oil or grease residues lag behind.

4. Sealing with silicone or repair paste

Now take that sealant at hand. Repair paste and high temperature silicone are heat resistant and universally applicable. These funds can be used anywhere, even on sleeves. Silicone is even flexible and dampens vibrations and the associated noises.

Wear that Agent on the damaged area on and elapse It evenly. In addition to covering the crack, cover a small area around it. This will take the tension out of the material and prevent the crack from expanding a millimeter or two and the same problem occurring again soon. Is the Damage too big and the sealant does not hold, usually only that helps Switch.

5. Assembly

If anything is unclear, take your photos or installation instructions and reassemble the exhaust as before. Change first Seals or rubbers if necessary. These usually only cost a few euros and swapping is almost no effort, but increases the durability.

Plug the Tube together and align them. Then fasten these again with the provided Ring and pull the Screws of connectors tight. Delete the Thread with copper paste to prevent it from sticking. Should still be during assembly excess sealant or repair paste to leave, remove Do this with a cloth.

6. Drying time and test run

Leave the exhaust for that specified drying time (usually 24 hours) and do not move the car during this time. Then do a short test drive by. Make sure that all symptoms are gone and that the volume is back to normal. Everything OK? Then the exhaust seal was successful!

Liqui Moly exhaust assembly paste

Quick sealing with exhaust bandages

The exhaust bandages provide a way to speed up Repairing damage to straight pipes However, they do not represent a real repair, but only a provisional emergency solution and the change is due soon. Warning: exhaust bandages can not at angles, Catalytic converter or rear silencer can be used.

The Application of the bandages is simple:

  • Park and lift the car after the journey
  • Roughly clean the damaged area
  • Wrap exhaust bandages around the still warm exhaust

Should you seal or change the flexible pipe on the car?

The flexible pipe is the flexible counterpart to the exhaust manifold. However, it has to withstand similar temperatures and loads. Here comes a flexible and complex steel mesh for use.

In the case of a leaky flexible pipe, that is Sealing does not make economic sensebecause this will not work with simple repair kits. Our recommendation is: That Changing the flexible tube instead of caulking is inexpensive and solves the problem.

How can I seal my exhaust manifold myself?

Small cracks in the exhaust manifold of the car can be sealed in most cases. But check that beforehand Relationship between cost and effort when sealing against changing. A new manifolds often only cost 5 to 15 € and after swapping, you even have a warranty for the new part.

1. Preparation

To seal the elbow, remove all of the pieces until you reach the elbow. Dismantle it to edit it. When simply changing, you skip the next steps and continue with the reinstallation.

2. Sanding and cleaning

Grind the crack with a drill with a sanding attachment so that it has a V shape receives. Drill at either end of the damage Hole 2 - 3 mmso that the crack cannot enlarge any further. Now sand the area around the crack with sandpaper. Remove rust, dirt and residues of grease or oil.

3. Seal the exhaust manifold

Wear the Plasticine evenly on the crack and roughly restore the shape of the elbow. Then leave the modeling clay for about Cure for 24 hours.

4. Assembly and test

After curing, build the Exhaust manifold and all dismantled parts back on. Subsequently start The car and check To see if the symptoms are resolved. If the sealing did not produce the desired result, either the cause is due to another part or you have to change the manifold.

Sealing the exhaust yourself - costs and effort

With our guide you can diagnose the defects and seal the exhaust yourself. The costs vary greatly and begin from about 5 € for repair paste or a new manifold gasket and are sufficient up to 50 € for complete repair kits. If you have to replace larger parts such as the rear silencer, the costs are of course significantly higher.

The tools required for sealing and changing can be found in a well-equipped home workshop or a rental workshop. The Workload is between 1/2 to 2 hours.

Have the exhaust repaired in the workshop

If the Damage to the car too great and parts are broken, you can have the affected parts repaired or replaced in a specialist workshop. This applies, for example, to serious damage to the exhaust manifold, center pot or rear silencer. Switching is the only option here. You will receive a replacement in the workshop New parts in original quality and the professionals will swap everything properly. The costs depend on the effort and the parts to change and range from 100 € for welding work up to € 700 when changing the catalytic converter.

Disclaimer of liability

Our guides contain a lot of technical information about the motor vehicle, which we have carefully compiled. However, these articles cannot replace the expertise of a specialist. Auto parts market is therefore not liable for damage and injuries caused by improperly carried out repairs. We generally recommend that work on the vehicle only be carried out by a specialist.

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