Over time, your car’s throttle body can become dirty and gummy with deposits. As those deposits build up, they can lead to a range of issues. The good news is that cleaning a throttle body is pretty quick and simple. No expertise required. Just trust the team at Castrol.
Before we take you through the steps, let’s answer some common questions.
What does a throttle body do?
The throttle body is a tube-shaped housing located between the air filter and intake manifold of a fuel-injected car. A butterfly valve, basically a flap, rotates to regulate the amount of air flow to the manifold. The throttle body is usually connected to the gas pedal with a cable or wire.
A common guideline is every 75,000 miles but it can vary. Cars that aren’t driven frequently or far distances may never need to be cleaned. Smaller vehicles and hybrids can often wait until 100,000 miles. Be sure to check your vehicle's owner’s manual for specific recommendations. A good rule of thumb is to check the throttle body every time you change your air filter. If it looks black or sooty, or there are gummy deposits in the throttle opening, it is time to clean it.
If you have your dealer or local repair shop do the work, it can cost anywhere from $200 – $300. On the flip side, a can of throttle body cleaner will cost you under $20. So DIYers will see huge savings.
Make sure you allow some time for the engine parts to cool down.
Safety first, for your hands and eyes. Those gloves will also help keep your hands clean from grease, grime and throttle body cleaner.
The air intake boot is a tube/hose that’s responsible for transferring air from the air filter to the throttle body plate. They are usually made of rubber and connected to the throttle body with a clamp. Depending on how the clamp is attached, you’ll want to use a flat-headed screwdriver or nut driver to loosen the clamp. Once loosened, slide the clamp down the boot, then remove the boot from the throttle body.
You’ll probably see one or two tabs on the sides of the connector. Press the tab(s) and the connector should slide right off.
Most throttle bodies are connected by a series of bolts. Loosen the bolts with your nut driver or socket wrench. Before you remove the final bolt, place your hand under the throttle body to make sure it doesn’t fall. Remove the throttle body gasket and inspect it. A compromised throttle body gasket can cause all sorts of running and idling issues, too. It might be tempting to reuse the old one, but it is much smarter and more efficient to replace it while you're in there. The gaskets are very inexpensive, and depending on your car, they should be easily available from a local parts store. If not, Amazon is likely to have them.
Place the throttle body on your rags or paper towels. Spray the throttle body cleaner inside. Use your toothbrush to gently clean the inside of both ends. Next, reach inside and open the round throttle body plate (also known as the valve). This is where a lot of dirt collects. Spray additional cleaner and use your toothbrush to clean all around the plate, including the edges. Then take some paper towels to wipe all around the inside of the throttle body to remove any remaining dirt and cleaner.
Pro tip: Insert the handle of a screwdriver to prop the throttle body plate open. This will make it easier to clean inside and will free up your hands.
Spray some cleaner on the throttle body where the gasket was attached and wipe with a paper towel. You’ll also want to wipe down the part of the manifold where the throttle body attaches. If any of the old gasket was stuck to the surface when you removed it, you’ll definitely need a new gasket. Be sure to gently scrape off any of the old gasket and be careful not to let old gasket material fall into the intake. That could cause serious engine damage.
You may see some dried dirt or even a piece of paper towel stuck in the throttle body. Spray some compressed air inside the throttle body, you’ll even want to spray air inside the bolt holes for good measure.
Set the gasket back onto the surface of the throttle body. Place one bolt through the gasket and throttle body and finger tighten to the manifold. Do the same with the remaining bolts. Tighten all the bolts in a crisscross pattern.
Slide the boot back onto the end of the throttle body. Then slide the metal clamp back to its original position and tighten.
That’s it! You just saved yourself a couple of hundred dollars and should see improved performance from your car.