FAI Auto guides the PMM audience through the twists and turns of the timing chain.
In the 30 years before the millennium, engine timing was the work of the chain, not the belt. Whilst the technology has been used on and off for decades, only prestige brands like BMW and Mercedes have consistently opted for chains over the quietness and easy maintenance of belts.
Failure reasons
In the mid-2000s, manufacturers utilised the advances in technology to produce chain setups that benefited from strength and longevity, often referred to as ‘fit for life’ products. What we’ve actually seen is that in most instances the chain is maintenance-free while in warranty periods but with more mileage and possible service neglect over the subsequent years, failures are very common. As workshops have seen increased demand for chains and associated components, chain kits have become more popular within the aftermarket.
Longer service periods set by manufacturers and owners’ delays in adhering to maintenance schedules can contribute to the deterioration of oil properties, something that is vital for a correct operating environment that a chain requires. Loss of oil pressure, decreased lubrication properties and particles in the oil system are the main issues behind the failures commonly seen.
Working closely with technicians, FAI has tested hundreds of oil samples that all tell the same story of oil problems.
It’s for this reason that we promote the use of manufacturer grade oil when fitting an FAI kit. For any engine to operate correctly, it must use the correct grade of oil as modern oils are very complex structures that are critical to an engine’s performance and long life.
This is particularly important when the valve timing is chain driven.
Recommendations
To enable today’s chain kit to survive it must be fitted to a clean and uncontaminated environment. FAI also recommends that the engine lubrication system be flushed just before work is started to remove the old timing chain kit. This will remove the majority of contaminants that will have built up over the life of the engine and during installation, the sump should be removed and inspected/cleaned along with the oil pump and pick up pipe.
