5 Ways to Clean Exhaust Manifolds - wikiHow (2024)

  • Categories
  • Cars
  • Car Maintenance and Repair
  • Exhaust and Fuel Parts

Download Article

Explore this Article

methods

1Find the Manifold

2Work Safely

3Remove the exhaust manifold.

4Clean the Exhaust Manifold

5Remount the Manifold

+Show 2 more...

-Show less...

Other Sections

Tips and Warnings

Things You'll Need

Related Articles

References

Co-authored byCharley Helvy

Last Updated: August 15, 2024

Download Article

Both gas and diesel combustion engines have manifolds. There are intake and exhaust manifolds in cars, trucks, motorcycles, and boat engines. Air and fuel mixtures enter the engine through the intake manifold, and fuel emissions exit through the exhaust manifold. The intake manifold and how it functions contributes to the engine's fuel efficiency. The exhaust manifold's job is to collect exhaust from the different engine cylinders and direct them out of the engine. The exhaust manifold is basically a pipe that leads to a catalytic converter and, then, through the muffler to the exhaust pipe. Of course, over time the manifold will collect dirt, dust, and corrosion. As this happens, the exhaust manifold loses efficiency in its job of releasing the gases, and it begins to foul the atmosphere, contributing to smog and endangering the driver and passengers. Even if you don't race your engines for sport or hobby, it is helpful to know how to clean exhaust manifolds on your own vehicles.

Get Car Support Solve Any Problem

5 Ways to Clean Exhaust Manifolds - wikiHow (3)

Hi there! Do you have a question about how to diagnose or fix a problem with your car? I’ve read the manual so you don’t have to. Select your make, model, and year, then ask away!

*

*

Method 1

Method 1 of 5:

Find the Manifold

Download Article

  1. 1

    Use your owner's manual to locate the exhaust manifold.

    • 4-cylinder engines have one exhaust manifold.
    • 6 or 8-cylinder vehicles have two manifolds.
    • Look for the manifold in front of the engine block on a front-end driven vehicle.
    • Find the manifold on the side of the engine block on a rear-driven.
    • This may vary slightly on boat engines or those on other small vehicles.
  2. 2

    Familiarize yourself with your manifold's design.[1]

    • Most exhaust manifolds are made of cast iron or a steel alloy similarly able to handle high temperatures.
    • Each manifold has an exhaust port matched to each exhaust outlet on the cylinder head.
    • The exhaust flows through these ports to a single outlet.
    • These ports are openings in an otherwise flat machined surface that fits with a gasket to the surface of the cylinder head.
    • Gaskets, made of paper, asbestos materials, or copper, serve as seals to prevent leakage between the manifold and cylinder head.
  3. Advertisement

  1. 1

    Wear safety equipment, including gloves, dust mask, and goggles.

  2. 2

    Allow the engine to cool completely for 30 to 60 minutes.

  3. Advertisement

Method 3

Method 3 of 5:

Remove the exhaust manifold.

Download Article

  1. 1

    Remove all the hoses that are attached to the manifold.[2]

  2. 2

    Spray the bolts on the manifold heat shield (usually found on recent cars) with lubricating solvent and remove with socket wrench.

  3. 3

    Remove all bolts on the manifold itself after applying lubricating spray solvent.

  4. 4

    Remove the manifold in a well ventilated work space.

  5. Advertisement

Method 4

Method 4 of 5:

Clean the Exhaust Manifold

Download Article

  1. 1

    Coat the interior of the manifold with lacquer thinner.

  2. 2

    Scrub coated areas with wire brush and steel wool.

  3. 3

    Use electric grinder to break up debris.

  4. 4

    Repeat the process throughout until you are satisfied with the look of the metal.[3]

  5. 5

    Wipe the manifold clean throughout with lacquer thinner.

    • Lacquer thinner is a solvent, but it also cures the metal with a coating that you can thicken with repeated applications.
  6. Advertisement

Method 5

Method 5 of 5:

Remount the Manifold

Download Article

  1. 1

    Match the ports to those on the cylinder head, and replace gasket before bolting manifold in place.[4]

  2. 2

    Contact your local dealer or research repairs in order to determine the precise sequence and torque level to follow when reinstalling the manifold.

  3. Advertisement

Community Q&A

Search

Add New Question

  • Question

    How do I stop carbon from going in the engine?

    5 Ways to Clean Exhaust Manifolds - wikiHow (24)

    Community Answer

    The only way is to not start the engine. Carbon comes from burning fuel.You can reduce carbon by making sure the thermostat is good (a hot engine makes less carbon) and by making sure your spark plugs, air cleaner and ignition system are in good condition, since fresh air and good sparks ensure a cleaner burn.

    Thanks! We're glad this was helpful.
    Thank you for your feedback.
    If wikiHow has helped you, please consider a small contribution to support us in helping more readers like you. We’re committed to providing the world with free how-to resources, and even $1 helps us in our mission.Support wikiHow

    YesNo

    Not Helpful 0Helpful 4

  • Question

    Can I jet wash the carbon deposit out of my exhaust without removing it?

    5 Ways to Clean Exhaust Manifolds - wikiHow (25)

    Community Answer

    No. The water and cleaner from the wash would end up inside the engine. Removing and jet washing is the only way.

    Thanks! We're glad this was helpful.
    Thank you for your feedback.
    If wikiHow has helped you, please consider a small contribution to support us in helping more readers like you. We’re committed to providing the world with free how-to resources, and even $1 helps us in our mission.Support wikiHow

    YesNo

    Not Helpful 0Helpful 0

  • Question

    Is it safe to drive if the exhaust manifold is blocked?

    5 Ways to Clean Exhaust Manifolds - wikiHow (26)

    Community Answer

    Exhaust flows from the head through the manifold/header. Theoretically it’s possible that the manifold could become blocked, preventing the engine from running, but that’s highly unlikely. Under normal conditions the carbon buildup that develops on the manifold is small and doesn’t significantly affect performance. If there was significant buildup to kill the engine, you would notice significant power losses prior to failure.

    Thanks! We're glad this was helpful.
    Thank you for your feedback.
    If wikiHow has helped you, please consider a small contribution to support us in helping more readers like you. We’re committed to providing the world with free how-to resources, and even $1 helps us in our mission.Support wikiHow

    YesNo

    Not Helpful 1Helpful 0

Ask a Question

200 characters left

Include your email address to get a message when this question is answered.

Submit

      Advertisement

      Tips

      • Consider taking manifolds to a paint stripping business where they will chemically strip the metal.

        Thanks

        Helpful0Not Helpful0

      • Bolts that hold manifolds in place are sometimes difficult to turn, but using a power wrench is not advised.

        Thanks

        Helpful0Not Helpful0

      Submit a Tip

      All tip submissions are carefully reviewed before being published

      Name

      Please provide your name and last initial

      Submit

      Thanks for submitting a tip for review!

      Advertisement

      Warnings

      • Do not use water or a water-based product to clean wrought iron, as the iron will absorb water and ruin the manifold.

        Thanks

        Helpful7Not Helpful4

      • Lacquer thinner emits toxic fumes, so be careful to work in area with good air circulation.

        Thanks

        Helpful5Not Helpful3

      Advertisement

      Things You'll Need

      • Safety equipment, including work gloves, dust mask, and goggles
      • Rags
      • Degreaser
      • Socket wrench
      • Lacquer thinner
      • Hand-held electric grinder
      • Stiff wire brush

      You Might Also Like

      How toKnow When a Muffler Is BrokenHow toPatch an Exhaust Pipe
      How toSiphon GasStep-by-Step Methods for Adjusting a CarburetorHow toChange a Fuel FilterHow toTest Fuel InjectorsHow toReplace a Catalytic ConverterHow to Replace the Fuel Injectors in Your VehicleHow toCheck Your Fuel PumpHas Your Catalytic Converter Been Stolen? How to Tell and What to Do If It Has BeenHow toClean a Fuel FilterHow toInstall an Exhaust SystemHow toReplace a MufflerWhat Causes White Smoke from Your Muffler (or Engine Bay)?

      Advertisement

      About This Article

      5 Ways to Clean Exhaust Manifolds - wikiHow (42)

      Co-authored by:

      Charley Helvy

      Automotive Expert

      This article was co-authored by Charley Helvy. Charley Helvy is an Automotive & Diesel Expert based in Avondale, Arizona. He is the founder of Charley’s Garage, an educational YouTube channel focusing on simple videos for automotive and truck enthusiasts. He has over 31 years of experience in the automotive world. He is a Diesel Instructor at the Universal Technical Institute and is a certified ASE Master Heavy Truck Technician. He offers training on gas and diesel engines on his YouTube channel, along with other DIY and explanation videos for beginners and enthusiasts alike. In 2024, he published a complete guide on Emissions Systems in Automotive and Diesel Vehicles. This article has been viewed 125,925 times.

      1 votes - 100%

      Co-authors: 7

      Updated: August 15, 2024

      Views:125,925

      Categories: Exhaust and Fuel Parts

      • Print
      • Send fan mail to authors

      Thanks to all authors for creating a page that has been read 125,925 times.

      Reader Success Stories

      • 5 Ways to Clean Exhaust Manifolds - wikiHow (43)

        Pure Energy

        Jun 20, 2020

        "Just knowing that someone is kind enough to put together so much info in this corporation-clogged world is a lot!..." more

      More reader storiesHide reader stories

      Did this article help you?

      Advertisement

      5 Ways to Clean Exhaust Manifolds - wikiHow (2024)
      Top Articles
      Latest Posts
      Recommended Articles
      Article information

      Author: Mrs. Angelic Larkin

      Last Updated:

      Views: 6236

      Rating: 4.7 / 5 (47 voted)

      Reviews: 94% of readers found this page helpful

      Author information

      Name: Mrs. Angelic Larkin

      Birthday: 1992-06-28

      Address: Apt. 413 8275 Mueller Overpass, South Magnolia, IA 99527-6023

      Phone: +6824704719725

      Job: District Real-Estate Facilitator

      Hobby: Letterboxing, Vacation, Poi, Homebrewing, Mountain biking, Slacklining, Cabaret

      Introduction: My name is Mrs. Angelic Larkin, I am a cute, charming, funny, determined, inexpensive, joyous, cheerful person who loves writing and wants to share my knowledge and understanding with you.