Rick's Free Auto Repair Advice

Induction Service — What is Air Induction Service?

What is Air Induction Service and Fuel Induction Service?

What is air induction service or fuel induction service?

Air induction service, also called fuel induction service is a cleaning procedure to remove carbon buildup from certain engine parts. The service can solve some performance related issues IF they’re caused by carbon buildup. Car makers do NOT recommend air induction service or fuel induction service and a preventative or routine service. It should only be performed to correct a carbon buildup related problem.

How does your engine get carbon buildup?

Most late model fuel injected vehicles have an electronically controlled throttle body. The throttle plate is opened and closed by a small electric motor driven by the vehicle’s PCM/ECM based on input from an electronic accelerator pedal position sensor. When the engine is off, the throttle plate is closed. At startup and idle, the throttle plate motor opens the throttle plate slightly to allow enough air into the engine to maintain idle and keep emissions low.

When you shut off the vehicle, hot fuel

air induction service

Carbon buildup in an electronic throttle body

vapors rise to the top of the vehicle and sometimes accumulate in the throat of the throttle body. As the residue cools, it forms a hard black carbon deposit. If the carbon buildup reaches a certain level, it can affect idle quality, resulting in a rough idle and even a no-start condition. During an air induction service, the technician cleans away the carbon buildup and performs a throttle body “relearn” procedure to re-establish a new “base level” fully clean position.

7T4Z-9E926-FA electronic throttle body

In addition to cleaning the throttle body, technicians also clean the Manifold Airflow Sensor (MAF) by spraying the

Mass Airflow Sensor

Mass Airflow Sensor

sensing elements with MAF sensor cleaner. Depending on the engine, the technicians may also perform a valve cleaning procedure where a “top engine cleaner” is injected into the air stream and allowed to soak on the back face of the valves for a period of time to dissolve carbon deposits. This procedure is used most often on newer style engines with Gasoline Direct Injection.

On older fuel injected engines, the fuel is sprayed through the valve opening and some gas hits the back of the valve. The fuel injection cleaners in the gas keep carbon buildup to a minimum. However, in GDI engines, where the fuel is sprayed directly into the cylinder, carbon can build up on the back of the valves. Over time, the carbon buildup on the valves can reduce performance. A valve cleaning procedure restores the valves to clean condition.

Do you need air induction or fuel induction service?

Car makers have published multiple service bulletins warning dealers not to perform routine air induction cleaning services, and to perform air induction service ONLY to correct a carbon buildup performance issue related issue. In those cases, an Air induction cleaning service CAN remove carbon buildup and restore performance. But it is NOT recommended as a routine preventative service.

Unfortunately, many shops are now recommending air induction service on just about every vehicle that passes through the shop. It’s a very profitable up-sell service, and in the majority of cases, it’s simply not needed.

Unless you have a specific performance issue like the ones listed below, you DO NOT NEED air induction service and should say NO when it’s “recommended.”

Performance related symptoms that may be corrected with air induction service

• Rough idle or hard starting caused by carbon buildup in the electronic throttle body. Make sure the shop confirms that the carbon buildup is the cause of the rough idle before agreeing to the induction cleaning service.

• Hesitation on acceleration caused by debris accumulation on the MAF sensor elements. You can clean the MAF sensor yourself with a spray can of MAF sensor cleaner. See this post.

• Rough idle and lack of power caused by carbon buildup on the back of valves in GDI engines.

Air Induction Service Fuel induction service cost

A complete air induction service takes about an hour, so shops usually charge around $150 for the service. The technician must remove the throttle body and clean it by hand. It should never be cleaned while in the vehicle and can’t be cleaned simply by spraying throttle body cleaner into the throat. The fluid can seep into the electronics and destroy them. The top engine cleaning and MAF sensor cleaning are done at the same time.

Air Induction Service is mostly a rip-off — but not always

As I said earlier; if you have performance issues that can be traced to carbon buildup, THEN an air induction service is worthwhile. However, if your engine is not experiencing any of the above mentioned performance issues, you do NOT need this service. It is most often NOT listed as a recommended service in the car maker’s maintenance schedule.

Want another opinion on fuel induction service? Read this post from the Dallas Morning News

©, 2018 Rick Muscoplat

Posted on by Rick Muscoplat



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