Skip to content
EN · km
Language
Units
My Garage

Squealing Noise From The Engine

A short squeal on start-up or when turning the steering is typical of a slipping accessory drive belt.

Normal risk

Usually not urgent, but have it checked. A broken belt can stop charging and power steering.

Short answer · Why does my engine squeal on start-up?

A squeal from the front of the engine that lasts a moment after starting, or when the air conditioning or steering loads the engine, usually comes from the accessory drive belt slipping. The belt may be worn, loose, or the tensioner or a pulley may be failing. Have it checked before it breaks.

On this page

Safe checks you can do

  1. Look at the belt with the engine offCracks, shiny glazed sides or missing ribs mean replacement.Never touch the belt with the engine running.
  2. Note when it squealsSqueal in damp weather or with the AC on points to a slipping belt.
  3. Watch the battery lightIf the belt slips badly, the battery light may come on.

Questions that narrow it down

  1. Does it squeal mostly on cold or damp mornings?Typical for a worn belt.
  2. Does it get worse with the AC or steering?More load makes a worn belt slip.
  3. Is there a chirp rather than a squeal?A chirp often points to a misaligned pulley.

Possible causes

Listed without ranking. Use the questions above to see which ones fit your car.

  1. Worn or glazed beltLess grip on the pulleys.
  2. Weak tensionerBelt is not held tight.
  3. Worn pulley bearingIdler or alternator pulley.
  4. Fluid on the beltOil or coolant reduces grip.

Questions about Squealing Noise From The Engine

Can I spray belt dressing on it?

It may hide the noise briefly but does not fix wear and can attract dirt. Replace the belt or tensioner if worn.

What happens if the belt breaks?

The alternator stops charging, and on many cars the water pump and power steering stop too. Stop safely.