* Power Steering Pump: This is a very common cause of whining noises, especially when turning the steering wheel or at low speeds. The whine often increases with steering input. Check the power steering fluid level; low fluid can cause whining and damage the pump.
* Alternator: A failing alternator can produce a high-pitched whine, especially under load (headlights, AC on, etc.). The whine might change in pitch with engine speed.
* Belt Tensioner or Idler Pulley: Worn or failing belt tensioners or idler pulleys can make a whining sound, often dependent on engine speed. You might also notice squealing, especially when starting the car or after it's been sitting.
* Wheel Bearing: A worn wheel bearing can make a whining or humming noise that increases with speed. This sound is usually more noticeable at higher speeds and might change depending on which direction you're turning.
* Transmission: While less likely to be a simple whine, transmission issues *can* manifest as unusual noises. This is more likely to be accompanied by other symptoms like slipping gears or difficulty shifting.
* Water Pump: A failing water pump can sometimes produce a whine, although this is less common than the other options.
To help troubleshoot:
1. Listen carefully: When does the whine occur? Does it change with engine speed, steering input, or vehicle speed? Is it consistent or intermittent?
2. Check fluid levels: Inspect the power steering fluid and engine coolant levels.
3. Inspect belts and pulleys: Look for cracks, wear, or looseness in the serpentine belt and pulleys.
4. Listen under the hood: With the engine running (and someone else holding the gas pedal steady), try to pinpoint the location of the whine.
5. Test at different speeds: Drive at various speeds to see how the noise changes.
If you're not comfortable performing these checks yourself, take your Saturn Ion to a mechanic for diagnosis. Providing them with the information gathered above will help them pinpoint the problem more quickly. Ignoring the whine could lead to more significant and expensive repairs down the line.
