Car squealing when accelerating
The buyer question: "car squealing when accelerating"
Arrange an inspection soon. Stop if the squeal becomes grinding or slapping, the temperature rises, smoke appears, or another warning light comes on.
What could cause it
More than one problem can cause the same symptom. These are places to inspect, not a diagnosis.
- A slipping or contaminated accessory belt
- A worn tensioner, idler, or pulley bearing
- A fluid leak reaching a belt or hot component
- Wheel or drivetrain slip that sounds similar from the cabin
Safe things to check
Keep clear of moving parts, hot components, and traffic. Use the owner's manual for vehicle-specific instructions.
- Note whether the sound occurs on cold start, acceleration, or when the A/C is switched on
- Look for visible fluid leaks or a damaged belt from a safe distance with the engine off
- Do not put hands, clothing, or tools near a running belt
Stop and arrange help if the sound changes to slapping or grinding, the battery or temperature light appears, smoke is visible, or the engine temperature rises.
What a mechanic may check
A mechanic may inspect belt routing and condition, pulley bearings, tensioner movement, fluid contamination, charging output, and the accessories the belt drives.
If you are considering this car
A seller may call a squeal a normal cold-start noise. Ask for the cause in writing and have the belt drive inspected before you decide whether to continue.
Questions for the seller
- Does the noise happen only when cold, under load, or with the A/C on?
- Has a belt, pulley, tensioner, or water pump been replaced?
- Are there fluid leaks near the belt drive?