High Revs When Idle

[Cobbdu1]

I'm new to the forum so I hope you can help and please forgive my lack of knowledge. I have a 2002 focus 1.6 petrol. Recently I've noticed very high revs when the car is idle i.e. when my foot is not on the accelerator. This does not always happen but will do most of the time, with revs around 1500 to 2000. Sometimes it corrects itself and revs lower to normal, other times I can lower the revs by lifting my foot off the clutch somewhat and the revs will, on occasions, stay low. However, it is clearly a problem.

I had some advice on the issue and have tried replacing the throttle position sensor and idle control valve, but neither has made any difference.

[FOCA]

A leak in the intake can cause this -

Check your air intake, and crankcase breathers (hoses that are connected to the air intake, throttle body, inlet manifold) etc for splits.

Also, the PCV valve can get "gummed up" with oily residue,

The idle control valve can give trouble and cause these symptoms

The ECU may actually be increasing the revs (to compensate for a fault) to stop the engine stalling it may "settle down" after a while/ after the engine is warmed up (but the fault may still be there)