| Subject: | carisma idle |
| Question: |
hi there got a 2000 carisma1.6 16v with a problem on idle,starting first thing in the morning starts fine then revs up to 2250rpm sits there until starts getting warm then settles down to 900,generally the tickover is moving from 500 to 900 at stand still,what could be causing this and what do you suggest?also got a whine in the gearbox any suggestions? |
| Answer: | Brian, A varible engine idle after the engine warms up usually indicates a faulty Idle Air Control (IAC) motor; also referred to as the Idle Speed Controller. It's a little eletrical motor attached to your throttle body that regulates a specific amount of air to enter your engine when your throttle plate is closed - i.e. when you're at idle. When the engine is cold, the car's computer tells the IAC to stay completely open to allow the max amount of air to enter; this is why your idle is much higher in the mornings. The varying idle speed once the engine warms up is sometimes called 'idle surge'. It's usually fixed by replacing the IAC. But have a mechanic check the IAC before replacing it because they can be expensive. A whining gearbox could indicate low or dirty fluid. You may need to
add some more fluid, or have the fluid and filter replaced. |