Timing Belts.

This is one of those subjects that has a plethora of information surrounding it. They are a maintenance item that has been fitted to a number of vehicles engines for some time now, and to an extent would be considered one of the more important items that need to be carefully considered during any vehicles lifespan.

**Side note - I will not touch on costs involved to carry out this process, because every engine with a timing belt fitted will be different, and labour times can vary drastically depending on what type of vehicle it is.**

So you've come to realise your vehicles engine is fitted with a timing belt. What does this mean? First we need to know what the timing belt is.

"A timing belt is a flat, toothed rubber belt that synchronises an engine’s valve and piston movement."

Below is an example of what that actually looks like. The particular example is a VW Golf 2.0L tdi.

To elaborate further on this, the timing belt keeps the crankshaft and the camshaft in time with each other, allowing for calculated combustion within the cylinders.

With this in mind we can start to see why this may be considered an important item within the maintenance schedule.

Being a rubber toothed belt, we know that rubber perishes. Which is why it is considered by the manufacturer to be replaced upon both a time and or Kilometre based schedule (which is a completely different topic to be discussed at a later date). You should always consult your owners manual to find the recommended schedule for your vehicle.

For some vehicles this can be a somewhat labour intensive process in gaining access to the timing belt. As such many personnel within the industry will often recommend the fitting of a kit, which would commonly include:

The timing belt

Timing belt tensioner assembly

Idler pulleys

Oil seals for camshaft and crankshaft

Sometimes these kits offered also include a water pump.

The main reason behind recommending a kit be fitted.

The labour time required to access the area may be high, meaning that by the time you have accessed the area to do the work, it may be more cost effective in the long term to replace all the serviceable components in the area while it is dismantled.

Timing Belt failures

Timing belt failures can occur for reasons including but not limited to:

Poor maintenance - Schedule of timing belt not being followed

Contamination - Oil soaked from leaking seals/gaskets

Idler pulley/Tensioner failure - Bearing failure within the idler pulley, thus collapsing and allowing the belt to shift from its desired position.

In the event of a timing belt failure, severe engine damage can occur. And will present a no-start condition for the vehicle.

With the majority of vehicles now running what is referred to as 'Interference Engines' in the event of timing belt failure, the piston will make contact with the valves located in the cylinder head.

Most often resulting in valve damage, which then requires the cylinder head be removed and damaged valves replaced.

The end result is that the engine will require costly repairs to rectify a timing belt failure.

By no means is this in anyway a 'scare tactic' ensued by your repairer to push you toward having this item maintained.

At the end of the day as a customer in any repair shop you have the last word on authorisation on any repairs being carried out to your vehicle. Whether that item be due or not.

If you have presented the vehicle to a repairer in a no-start condition and they have diagnosed the issue to be with the timing belt and you do not wish to carry out the repair, there may be a diagnostic charge applied.

I hope to have covered this subject in as much detail required to make an informed decision regarding timing belt maintenance.

If you do have any further questions or queries you can contact me regarding this topic.