Checking the Idle Control Valve (ICV)

From BMW E34 Encyclopedia


The idle control valve (ICV) is used to regulate the amount of air entering the intake manifold. Symptoms of a bad control valve are inconsistent [[Idle_Specifications|idle] speed, high [[Idle_Specifications|idle] speed, and [[Idle_Specifications|idle] idle speed.


  • Unscrew the bolts that mount the air intake to the frame
  • Unscrew the clamps that connect the intake boot to the throttle body. Make sure not to misplace the two o-rings
  • Disconnect the intake boot by pulling it forward off the throttle body. Move the idle control valve up and down while gently pulling it away from throttle body to remove it

It might be difficult to plug the ICV back inside the throttle body. Try inserting the ICV by rotating it counter or clock-wise


Spray a healthy amount of brake cleaner inside the ICV. Moe the unit around move and shake it. Rinse and repeat until the valve is clean. Let it dry for a few minutes before reinstalling. There is no need to use a Q-Tip, but if you must, make sure the valve does not close and get clogged with cotton particles.

Resistance Testing[edit]


Load Testing[edit]

With ICV connected to the harness, put it in the position where the internal valve is either open or closed. Turn on the ignition. The valve must force itself into a half-open position.