Timing chain problems are not uncommon, and perhaps a little too frequent in some particular makes (Holden might be one of these).
Just like any other moving mechanical components inside an engine, a timing chain is subject to wear. A timing chain is lubricated by the engine oil. Lack of oil changes, low oil level or poor oil quality can cause the timing chain to wear faster. As it wears it can stretch placing enormous stress on the entire engine.
A timing chain is kept under proper tension by a chain tensioner. A chain tensioner could be operated by a spring-loaded mechanism or oil pressure. Chain guides and silencers are used to keep the timing chain from vibrating. All these components wear too.
How can you tell if the timing chain is worn?
Often, when the timing chain is worn the engine may feel sluggish, low on power or have troubles starting. This is because as the chain wears out, it stretches and the ignition and valve timing becomes more delayed. A worn timing chain, guides or chain tensioner can also cause a variety of noises originating from the timing chain cover area of the engine. The timing chain noises can range from rattling to whirring, whining or buzzing.
To avoid timing chain problems we strongly recommend the careful regular maintenance of your engine at (or if possible ahead of) the recommended intervals. Using premium quality engine oils and oil filters will also help. Keeping the proper oil level will ensure that the timing chain is always lubricated. In a well-maintained engine, a timing chain can last the life of the vehicle. Sadly though this isn’t always the case.