Timing belt inspection, maintenance and replacement


Here it is, the dreaded timing belt - another relevant and informative topic to write on.

Whenever we speak to customers and tell them that their timing belt is due, you can almost see their hearts drop. Well, it’s either that, or they have no idea what we are talking about.

So let me give you some basic technical information as to what a timing belt does. For starters, not all cars have timing belts - a lot have timing chains which don’t need to be changed unless there is an issue with them. In this case, the cars will usually have a rattle, run rough, or have trouble starting. Timing belts, however, have to be changed according to the manufacturer's specifications of either time or kilometres.

A timing belt is responsible for making sure the pistons that drive the engine, go up and down in the correct order, and that the valves that seal the engine above the pistons open and close at the correct time. It does this by driving the cam shafts and crank shafts respectively. In basic terms, it makes sure the pistons don’t smash into the valves causing engine failure.

So now that we may have a basic understanding of what a timing belt does, you may ask: why we can’t just change it when we can see that it is wearing? The short answer is that - really, we could just do that. However, to be able to gain access to timing belt, to check them, the labour is very time intensive - 3-4 hours sometimes - that you may as well change it whilst you are there. It would be silly to just check it and pay for all of that labour. This is why car manufacturers have a recommended change time based on age of car or the kilometres that have been driven.

When having your timing belt done, you may be offered a couple of ways of doing it. Firstly and usually, the cheapest is to just change the timing belt itself - however I do not recommend doing this. There are tensioners and seals that sit behind the timing belt that help the timing belt to move, so you would be crazy not to service at the same time. If any of those fail, it will still cause engine failure. In fact, we won’t even offer this option to our customers.

The next option you may be given is the water pump. This - usually, but not always - sits behind the timing belt. We always say to our customers that if it looks like it is leaking, it is worth changing whilst you have the timing belt off, so that you don’t have to pay for the labour all over again. This way, everything that may need to be changed, is all done in one hit. We would usually change the drive belts (or fan belts as some of you may know them as), if they are looking worn - as you have to take them off to gain access to the timing belt.

We had a customer a few weeks back that had been putting off having her timing belt done because she couldn’t afford it. We finally did and - thank goodness -, because when we did, it looked like it was seconds away from breaking!

Timing Belt Replacement in Dianella

Those wear marks on the belt shouldn’t be there, the teeth of the belt are on the other side. If these had gone through, the timing belt would have snapped and caused catastrophic engine failure.

So when your mechanic tells you your timing belt is due, either by time or kilometres - please, please don’t put it off. It will make sure your engine keeps running the way it should.

Have a great weekend!


P. S. If you ever have any questions or topics you would like me to cover, please don’t hesitate to drop me a line.

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Specialist Car Services