How to Clean a Throttle Actuator Bore

The throttle bore or throttle actuator as they are called it on newer cars is used to meter the engine air intake thus controlling the engine RPM and power output. The throttle actuator is a normal service item and each manufacturer has their own design when it comes to the throttle system of an engine, the principle remains the same.

What goes wrong?

As the engine operates large volumes of air are processed which leaves behind deposits that can hinder the actuators operation and deflect air flow in an undesirable manner causing the engine to stumble (hesitate), hard starting and limp mode conditions. When these deposits called coking become sever enough the car's computer will detect a correlation mismatch and reduce the power of the engine as a safety precaution.

Throttle Actuator Service

  • Can help stop the engine from stalling at idle
  • Fix a stumble off idle
  • Is part of a Tune up
  • Will cause the engine to go into limp mode
  • May need reprogramming if serviced incorrectly.
  • Can alleviate hard starting
  • Can normally be done in about 20 minutes
  • Is a DIY service.


There are generally three types of throttle actuator.

  1. Cable Operated - This is the most forgiving of actuators and will need no special care other than service.
  2. Gen 1 Electronic - (About 2000 to 2009) To service these actuators you must disconnect the battery to avoid programming issues.
  3. Gen 2 Electronic - (About 2009 to present) These units must be serviced with the wiring connector still connected to the actuator (it can be unbolted) and it cannot be forced open or it will cause programming issues. In the shop one technician will open the throttle actuator with the key on while depressing the gas pedal while an additional technician performs the service.

Where is it?

 The throttle actuator is located at the intake manifold air inlet between the air intake tube and main intake manifold body on top of the engine toward the front in most cases. Some throttle actuators have engine coolant that runs through the unit to help heat it help to improve cold starts and improve mileage.

What's the cost?

The location of the actuator will determine the cost of the service which is typically about $65.00 to $95.00 US if the job is done at a shop. Supplies to do the work includes a can of throttle bore cleaner (carburetor cleaner) and a shop towel, for the DIYer, about $15.00 US.

Let's See!

  1. Start by disconnecting the battery, this will prevent triggering computer issues when doing the repair. Locate the air intake tube and loosen the clamps and mounting bolts to remove it. (Leave the wiring connected if newer than 2009). Older vehicle's utilize a throttle cable which must be removed, along with transmission and cruise control cables.
  2. Remove the actuator wiring connector which could have a safety clip that will need to be removed before the connector can be disconnected.
  3. Some actuators have coolant running through them which will need to be drained and then refilled once the job is complete. Disconnect the hoses and continue removing the mounting nuts. Remove the sealing gasket or "O" ring seal and clean or replace. Use carburetor cleaner and a shop towel to clean the intake inlet.
  4. Clean the throttle actuator bore housing and butterfly both the front and back sides including the pivot shaft. Looking from the rear of the throttle bore coking deposits are observed which is caused by impurities in the air causing the engine to idle erratically. After installing the throttle bore, insert and evenly tighten mounting bolts or nuts. Reinstall vacuum, bypass and breather tube lines while reconnecting the electrical connectors. Reconnect throttle cables and reinstall the air intake boot, clear any codes if necessary. 

Watch the video!

How to Service a Throttle Actuator.


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