Throttle body removal and replacement on a 4-cylinder Saab 9-5.

Tools and supplies:

  • 10 mm socket: throttle body and cable cover bolts;
  • 13 mm or 1/2" wrench: negative battery clamp;
  • flat screwdriver: delivery pipe boot clamps, limp home mechanism reset;
  • pliers: coolant hose clamps;
  • new rubber seal (#9176918) and vaseline;
  • torque wrench.

The throttle body is located under the plastic engine cover -- it's where the delivery pipe leads to.

Disconnect the battery and unscrew the cap on the coolant expansion tank to releave the pressure. Put the cap back on.

Undo the clamps on the delivery pipe and take the rubber boot off. On newer cars with a plastic delivery pipe (and no rubber boot) you might have to first slacken the delivery pipe retaining bolt on the cylinder head.
Cable cover

If you were to clean the throttle body, then you'd stop here, just clean it inside and put the pipe back. However, to replace the throttle body, you need to do more. Continue with removing the cover over the throttle cable (two 10 mm bolts).

Disconnect the accelerator pedal cable from the throttle body's pedal arm.

Unplug the wiring connectors from the limp-home solenoid and the throttle body.

Detach four hoses entering the throttle body. The two bigger hoses may contain some coolant, so be careful if the engine is hot. WIS recommends clamping them first to prevent coolant spillage.

Undo three 10 mm bolts and lift the throttle body off the intake manifold.
Last hose

Undo the hose clamp on the back of the throttle body and detach the hose. Congratulations, you have just removed your throttle body ;).
Old and new

Two throttle bodies side by side. I'm installing a used unit (right), and it actually appears to be dirtier on the outside. Cleaner on the inside though.
New and old

Note how the end of the spring is caught in the triangular tab on the old unit (right). It's an indication that the limp-home solenoid has fired and locked the pedal arm to the throttle butterfly.
Limp home reset

If you ever need to reset a previously activated limp-home mode, it can be done directly on the car. Move the end of the spring towards the throttle body to release it from the tab on the pedal arm, and then turn the black toothed disc anti-clockwise, about a centimeter, until it clicks. Now try moving the black plastic pedal arm to make sure that the metal throttle body arm (the lever pointing to the right) is not following it anymore.

Install a fresh rubber seal and coat it with vaseline.

Start by connecting the hose on the back of the throttle body and continue in reverse order. The bolt tightening torque is 7.4 ft-lbs.

  [expand all]



Copyright © 2000-2013 Dmitry Platonoff
All rights reserved.