Throttle body and carburettor cleaner: how to use it

Parkers explains how to clean your car's throttle body to restore smooth idling and running of your car's engine.

Spraying throttle body cleaner onto a throttle body

by Chris Williams |

You’d be amazed at how much car maintenance you can do yourself. There are the super basics such as checking tyre pressure and refilling windscreen washer fluid. But there are perceivably more complex tasks too such as changing air and oil filters and restoring hazy headlights, which are in fact straightforward, very satisfying to do, and simply require a little guidance.

Cleaning your car’s throttle body sits in the latter camp. Though, with cleaning a throttle body, it’s not so much a case of perceived complexity, but rather being aware of it at all.

This is a guide to your car’s throttle body, and how to clean it.

What is a throttle body?

A car's throttle body
©Photo: Getty Images

The throttle body regulates how much air goes into the engine to mix with the fuel. Modern cars use electronics to connect the accelerator pedal to the throttle body and to calculate how much fuel to inject into the combustion chamber depending on the volume of air coming in. The throttle body, therefore, has a very important job and needs to be clean and in good condition.

You can see what it looks like in the image above. It sits between the intake manifold and the air filter and is made from aluminium. It is likely covered by an air duct that connects the air filter and throttle body.

As the fuel and air combust in the chambers, carbon deposits accumulate on the throttle body, which can have detrimental effects on how your car’s engine runs.

Symptoms of a dirty throttle body include rough idling and engine running (including misfires), and stalling. These symptoms occur because the clogged or dirty throttle is unable to draw in the correct volume of air required and creates a bad fuel-air mix. The throttle body’s idle sensor can also be affected and not work properly. You should consider cleaning the throttle body every 20,000 miles or so.

What does a throttle body cleaner do?

It’s an apt name. Throttle body cleaner is an aerosol spray that you apply to a dirty throttle body and can be used alongside an old toothbrush or similar to remove dirt and grime.

Below are the best throttle body cleaners:

Holts EGR & Carb Cleaner 500ml

Editoru2019s pick
Holts EGR & Carb Cleaner 500ml
Amazon

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Very effective and great value, Holtsu2019 EGR and Carb Cleaner is our top recommendation. It can be used beyond cleaning a throttle body and carburettors, and also for air intakes and exhaust gas recirculation (EGR) valves.

Wynn's Air Intake & Carburettor Cleaner 500ml

Runner up
Wynn's 54179 Air Intake & Carburettor Cleaner 500 ml
Amazon

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Also a very effective throttle body cleaner. Unless youu2019ve got an old classic car, itu2019s unlikely youu2019ll use it to clean carburettors, but if you do, itu2019s excellent for that too.

S.A.S Throttle Body Cleaner 500ml

Third place
Sas Throttle Body Cleaner
Amazon

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These three products are all very similar and perform very well. The SAS Throttle Body Cleaner is worthy of a podium place and can be used in the same way as the Wynnu2019s spray.

Sealey Throttle Body & Carb Cleaner 500ml

From a popular name
Sealey Throttle Body & Carb Cleaner 500ml

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We know that many home mechanics are dedicated users of Sealey tools and that is fair enough. Its throttle body cleaner is good too and if itu2019s a name you wish to stand by, this spray allow you to and wonu2019t let you down.

How to clean a throttle body

Gather together the tools you’ll need first. These will be:

Screwdrivers (torx), sockets and pliers to remove the air duct - important note: if you are unable to remove the air duct leave throttle body cleaning to a professional.

Throttle body cleaner

An old toothbrush or similar for stubborn dirt

Paper towels to wipe away grime

Step by step:

  1. Park your car somewhere well ventilated and with plenty of working space. Use an inspection lamp if you wish.
  1. Disconnect your car battery’s negative terminal to prevent any risk of short circuiting.
  1. Locate the big air duct that connects the air filter and throttle body. Carefully remove it by loosening its clamps with a screwdriver, or whatever tool you need, along with any other hoses that need to be in order to access the throttle body. You may not need to remove the duct fully, but removing the air duct might require some gentle wriggling. Labelling the hoses helps you remember where to reconnect them afterwards. Avoid disconnecting any obstructing wires unless you’re sure about it.
  1. Now with access to the throttle body, spray the inside of the throttle body with cleaner. Be very careful not to let anything fall into the throttle body. Scrub any stubborn residue loose with the toothbrush and wipe away with the paper towels. Continue until the metal is completely clean. When finished, make sure the throttle body is totally dry and the surrounding area if there has been any spillage.
  1. Replace the duct and clamps, tightening to the same degree they were before.
  1. Remove your tools before reconnecting the negative battery terminal.
  1. Start the engine. Do not worry if there is initially some rough idling or white smoke from the exhaust. There may be some throttle body residue that needs to burn off; additionally, modern cars’ electronic brains sometimes have to recalibrate after the battery has been disconnected.
  1. Let the car idle for a couple of minutes and take for a test drive if you wish. If the throttle body was very dirty you may notice an improvement in performance and even economy. Ultimately, cleaning a throttle body is one task in the overall upkeep and longevity of your car’s engine.

Read next:

The best degreaser for cleaning your engine and car

Giving your car a health check at home: Parkers explains

Rust converters and rust repair: Parkers' 'how to' guide

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