Try this 10-minute throttle cleaning fix to solve a rough idle problem and save the cost of taking your car into the shop.
Disconnect the air duct from the throttle body. Disconnect and mark any electrical connectors or vacuum lines you remove.
Locate the throttle cables and rotate the throttle plate. Spray throttle body cleaner around the inside of the throttle body.
Shoot compressed air into the throttle body to dry the spray solvent. Reinstall the ductwork and attach the vacuum lines and electrical connectors.
If your car runs rough when idling, the cause just might be a dirty throttle body. The throttle body controls the amount of air the engine takes in, and when it gets dirty, the engine can't idle smoothly. So before you take the car into the shop, consider taking 10 minutes and cleaning it yourself with a spray can of throttle body cleaner and paper towels. You just might save a bunch of money and there's a good chance you'll cure the problem.
Here's how the throttle body gets dirty. When an engine shuts down, hot exhaust gases and unburned fuel float to the top of the engine. As the vapors bake from the engine heat, they form black sooty carbon deposits inside the throttle body.
Follow the plastic duct from the air filter housing up to the throttle body. Remove the duct and locate the throttle cables and rotating mechanism. Rotate the throttle mechanism and spray the cleaning solvent around the inside of the throttle body. Give it a moment to work and then wipe out the crud.
Have the necessary tools for this DIY project lined up before you start—you’ll save time and frustration.
You'll also need plastic gloves.
Avoid last-minute shopping trips by having all your materials ready ahead of time. Here's a list.