One of the few remaining serviceable components in gasoline engines is the throttle body. Here’s why your mechanic wants to clean it.
The tune-up, as it was once known, has come and gone. Nobody misses it. Yet, we all knew what a tune-up entailed after nearly a century of paying for them.
In modern cars, many maintenance intervals have extended almost to the life of the car. It may need its oil changed once or twice a year, and there is a cabin air filter to change a few times on your way to 100,000 miles, but there’s not much more to do until the big single service involving a timing belt change and spark plugs at around that point.
However, there is one component that mechanics like to clean when cars run rough, have a rough idle, or out of an abundance of caution. They like to clean your throttle body.
Your engine is a giant air pump. Outside air enters through the air intake at the front of your vehicle and then travels through the engine air cleaner element. That helps remove dust and debris so that it doesn’t enter the combustion chamber and cause trouble. The air then flows through a tube to the throttle. The throttle is what controls the airflow into the engine and the assembly that houses and works with the throttle is known as the throttle body.
Years ago, there would’ve been a carburetor where the throttle body is. A carburetor also metered the volume of air that went into the combustion chambers, but it served a second purpose, too: It mixed air and gasoline into a fine mist. Modern engines directly inject fuel into the combustion chambers via fuel injectors, so the throttle body is only a valve that allows air to pass.
Although the air cleaner element does remove solids, there’s a lot going on under the hood that can cause gunk to form, which can impede the smooth operation of the throttle. Mechanics will use a solvent spray, and sometimes a brush, to remove the gunk and free up the throttle so it works freely.
In certain situations, this is a first step in solving problems. There is an mass air flow (MAF) sensor and a throttle position sensor (TPS) that can fail and cause similar running conditions, but they are more expensive than a shot of solvent. Mechanics often start with the cleaning.
Every throttle also has a mechanism to actuate it based on the demands of the driver’s right foot and the signals from the engine. In older cars, like this 1992 Miata, it is a mechanical throttle linkage — literally, a cable connected to the gas pedal that yanks the throttle open. In all new cars, it is an electronic throttle body actuator, which replaces the mechanical cable with a wire that sends electrical impulses to the throttle body actuator, telling it to open and close.
Anything that moves is likely to stop moving eventually. Some popular cars have had issues with the electronic throttle body. So keeping the throttle clean is always a wise preventative maintenance step.
The question is whether the service cost is worth it. RepairPal.com suggests that a throttle body cleaning costs between $226 and $290. What’s interesting to note is the price of parts: $6 to $12, the low estimate of which is about twice the cost of a can of CRC Throttle Body Cleaner at your average auto parts store.
Cleaning a throttle body is a lot simpler than changing your oil. If you can follow simple instructions and depress the button a spray can, you can do it yourself. For three bucks and five minutes worth of work, you might be able to save yourself hundreds of dollars in labor charges with a mechanic.
Image Credits: Top of page image by John Goreham. Second image courtesy of Ford.