Timing Belt Replacement Guide

Timing belts are an important maintenance item on many engines. Replacing the belt at the correct interval can help prevent serious and expensive engine damage.

Download Printable Timing Belt Guide

What Does a Timing Belt Do?

The timing belt helps keep important internal engine components synchronised. Because its job is critical, timing belt maintenance should not be ignored.

Keeps the Engine in Time

The timing belt synchronises the rotation of the crankshaft and camshaft so the engine's valves operate at the correct time.

It Is a Wear Item

Timing belts do not last indefinitely. Age, mileage, heat and operating conditions can all contribute to belt deterioration.

Failure Can Be Expensive

On many engines, a failed timing belt can allow internal engine components to make contact and cause major engine damage.

REPLACEMENT INTERVALS

When Should a Timing Belt Be Replaced?

There is no single replacement interval that applies to every vehicle. The correct interval depends on the manufacturer, engine, model, mileage and age of the vehicle.

Some manufacturers specify replacement primarily by mileage, while others also specify a maximum time period because the belt can age even when the vehicle has travelled relatively few kilometres.

Check the manufacturer's service schedule
Consider both vehicle age and mileage
Check whether previous replacement history is available
Do not assume a low-mileage vehicle has an unlimited belt life
Replace the belt when the specified interval is reached

Don't Know When It Was Last Replaced?

If you bought the vehicle used and there is no reliable record of timing belt replacement, it is worth checking the service history and manufacturer requirements.

Guessing about the age of a timing belt can carry unnecessary risk, particularly on engines where belt failure may cause internal damage.

Possible Timing Belt Warning Signs

A timing belt can sometimes deteriorate without giving an obvious warning. Scheduled replacement is therefore more important than waiting for symptoms to appear.

Unusual Engine Noise

New ticking, rattling or other unusual noises from the timing area should be investigated rather than ignored.

Engine Running Problems

Poor running, misfiring or changes in engine performance can have many causes and should be diagnosed properly.

Difficulty Starting

Starting problems can result from many different faults. If timing is suspected, the engine should be checked before unnecessary further cranking.

Visible Belt Damage

Where inspection is possible, cracking, damaged teeth, fraying or contamination can indicate that the belt requires attention.

Oil or Coolant Contamination

Fluid contamination in the timing-belt area may damage the belt and should be investigated together with the source of the leak.

Unknown Service History

No replacement record is not a mechanical symptom, but it is an important reason to confirm when the timing belt is actually due.

TIMING BELT KIT

What Is Usually Replaced With the Belt?

Depending on the engine design and manufacturer requirements, timing belt replacement may involve more than replacing the belt itself.

Timing belt
Tensioner
Idler pulleys where applicable
Associated seals where required
Water pump where appropriate for the engine
Coolant where the cooling system is opened

The exact parts required should be determined for the specific vehicle and engine.

Why Consider the Water Pump?

On some engines the water pump is driven by the timing belt or is located behind the timing-belt assembly.

Where appropriate, replacing the water pump during timing-belt work can avoid repeating much of the same labour later if the pump fails.

Why Timing Belt Maintenance Matters

Preventative timing belt replacement is generally far preferable to dealing with the consequences of an unexpected belt failure.

Protect the Engine

Replacing the belt at the correct interval can reduce the risk of serious internal engine damage caused by belt failure.

Avoid an Unexpected Breakdown

A failed timing belt can stop an engine without warning and leave the vehicle unable to continue.

Plan the Maintenance

Scheduled replacement allows the work to be planned rather than dealing with a potentially much larger repair after a failure.

SERVICE HISTORY

Information Worth Keeping

Once the timing belt has been replaced, keep a record so the next replacement interval can be planned properly.

Date of timing belt replacement
Vehicle mileage at replacement
Parts that were replaced
Water pump replacement if applicable
Next recommended replacement date or mileage
Invoice or service record

Not Sure If Your Timing Belt Is Due?

Tell us your vehicle make, model, engine, current mileage and any available service history. We can help you determine the next step.

Ask Probert Auto

Is Your Timing Belt Due?

Contact Probert Auto with your vehicle details and mileage and we can help you arrange an inspection or timing belt replacement quote.

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