* Worn Bearings: This is the most likely culprit. The bearings within the supercharger's rotor assembly are constantly under high stress. Over time, wear and tear from friction and heat degrade the bearing surfaces, leading to noise. The squeal will often increase in pitch and intensity as the supercharger speeds up.
* Lack of Lubrication: Insufficient lubrication is a major contributor to bearing wear. Problems with the supercharger's oiling system (low oil level, clogged oil lines, or a faulty oil pump within the supercharger) can lead to premature bearing failure and squealing.
* Bearing Damage from Debris: Foreign material, such as metal shavings or dirt, can get into the supercharger and damage the bearings. This can be caused by a worn-out air filter, improper maintenance, or an internal supercharger failure.
* Loose Pulley: While less common, a loose pulley on the supercharger shaft can cause a squealing noise as the belt slips or the pulley wobbles.
* Belt Tension: An excessively tight or loose supercharger drive belt can also contribute to a squeal, though this is usually more of a high-pitched whine rather than a bearing-type squeal.
Distinguishing Bearing Squeal: A bearing squeal is typically a high-pitched whine or screech that changes pitch with engine speed. It often increases in intensity as the supercharger's RPM increases. A belt squeal, on the other hand, is often more consistent in pitch and may be accompanied by belt slippage.
What to do: Do not continue to drive the car with a squealing supercharger. Prolonged operation with a failing bearing can lead to catastrophic supercharger failure, potentially causing further damage to the engine. You should have a mechanic inspect the supercharger as soon as possible. Repair might involve a simple bearing replacement (if caught early), or it may require a complete supercharger rebuild or replacement. Ignoring the problem will almost certainly result in more expensive repairs later.
