What Does A Timing Belt Do?

timing belt kits

What Does A Timing Belt (Cam Belt) Do?

A timing belt, in some countries also known as a cam belt, is what maintains the synchronization of the crankshaft to the camshaft(s). The camshaft is what controls the timing of the intake and exhaust valves in the combustion chamber.

What Is A Timing Belt Made Of?

The durability of timing belts has improved greatly over the last 20+ years as material sciences have advanced along most other technologies. The newer materials withstand heat, oil and the elements much better than older belts but will still need to be changed at the recommended replacement interval.

Modern timing belts are made of a rubber compound of molded polyurethane, neoprene or welded urethane.

Timing belts grip the pulleys by way of teeth that have different characteristics depending on the application.

What Are The Differences Between A Timing Belt And A Timing Chain?

Most new engines utilize a timing chain in place of a timing belt but there are still many vehicles on the road with timing belts and it is important to know what your vehicle has.

A timing chain, like the name suggests, is a chain made of links much like a bike chain whereas the timing belt is a belt made of a rubber compound.

You can check if your vehicle has a timing chain or belt in our Belt Or Chain list here.

Timing Belt Pros:

  1. Quieter and smoother engine operation
  2. Failure won’t be catastrophic if your engine is non-interference
  3. Higher engine efficiency
  4. More economical engine construction
  5. No sprocket or tooth wear

Timing Chain Advantages:

  1. Generally good for the lifetime of your vehicle
  2. Higher load strength

Signs Or Symptoms You Need A New Timing Belt

Age- timing belts generally have a replacement interval of 60,000 to 120,000 miles or 5 - 7 years. Check with the manufacturer/dealership for your particular model. An outwardly fine looking belt may still have weakened significantly and will still need replacing if its at the end of its lifespan.

Cracks- most engines have a timing belt inspection hole in the timing belt cover in which you can visually inspect the belt. If you see any cracks in the timing belt it is time for a new one.

Misfires- It is common for a worn belt to jump teeth which will set your timing off and cause your engine to run poorly.

Engine won’t start or run- Obviously there can be many reasons why an engine won’t run but a broken timing belt will definitely prevent your vehicle from running.

Noise- A ticking sound emanating from the engine or whirring noise can signify a worn or failing timing belt

IMPORTANT: Interference Or Non-Interference Engine

If the timing belt breaks on an interference engine the valves will come in contact with the pistons and damage the pistons, valves, heads and cylinder bore resulting in a very expensive repair bill.

No critical damage will occur if the timing belt breaks on a non-interference engine but the car will still need a tow to get it to the repair shop.

Check Here or with the manufacturer on whether your vehicle has an interference or non-interference

Other Components Related To The Timing Belt And/Or A Timing Belt Change

A timing belt change is quite labor intensive and requires removing alot of engine components and covers to access the belt. For this reason it makes economic sense to replace other parts that are normally hard to access but are now easily accessible while doing the timing belt change.

Timing Belt Kits usually include some of the following parts.

These parts include:

Water Pump- the water pump or gasket can fail leading to coolant leaks and engine cooling problems. Leaking water pump gaskets could allow coolant onto the belt thereby weakening it.

Belt Tensioner- A sign of a tensioner failing is a ticking noise. When a tensioner gets weak it may allow the belt to loosen and jump timing, weaken or break.

Main Seal And Cam Seal(s)- Leaking main and cam seals will expose the belt to engine oil which could lead to premature failure.

Balancer Shaft- Some engines have a balancer shaft that is designed to offset the engine’s vibrational forces and smooth out the engine. This is generally belt driven and the belt should be changed at the same time as the timing belt.

Idler Bearing- Idler bearings are pressed into the idle pulley and are responsible for guiding and tensioning the engine drive belts.

Can You Replace A Timing Belt Yourself?

If you elect to do it yourself and have all the required tools a timing belt itself only costs around $20 - $50 USD with things like the water pump and tensioner adding another 50 USD or so.

Alert: Be Sure To Buy A High Quality Belt And Components

There are cheap belts online whose quality may be questionable. Many belts come with a warranty against premature failure. It is preferable to go with OEM parts in many cases.

If you take your vehicle to a professional shop expect to pay an additional $300 to $1000 USD depending on the make and model of your vehicle.

Tools Needed To Replace A Timing Belt

  • Jack
  • Jack stands
  • Wrench set
  • Pulley puller
  • Hammer, screwdrivers
  • Locking Timing Tool Kit - Helps ensure camshaft alignment during removal and installation of the timing belt