TIMING CHAINS

Lots of vehicles now have timing chains. Some have chains and belts combined. When they were re-introduced a few years ago everyone thought it would be a good thing but unfortunately this is not the case. The old types used to have a tensioner that always kept the tension on the chain, whether the engine was running or not, always adjusting for wear. They would have a toothed ratchet so couldn’t drop back to let the tension go slack. The new types rely on oil pressure.

Service intervals are set by the manufacturer and are fifteen to twenty thousand miles [or more] apart. Even though the oil filters and oil are designed to last this long ,some times owners push the service intervals longer or don’t do the miles each year . As a result the oil filters are left in the engine for extended periods and we have had cases when engine damage has resulted as the oil filters start to break up ,restricting oil flow and causing low oil pressure resulting in inadequate chain tension causing engine failure.