The Discovery 3 and 4's 2.7 and 3.0 litre TDV6 diesel engines use a timing chain rather than a belt, and chain stretch is one of the most talked-about issues on the used market.
Timing chain stretch is usually linked to neglected servicing — infrequent oil changes let sludge build up, accelerating wear on the chain and tensioners. It's rarely an issue on well-maintained, regularly serviced examples.
A rattling noise on cold start-up, engine warning lights, or rough idling can all point to chain wear. Left unaddressed, a stretched chain can jump timing and cause serious engine damage.
Always ask for full service history and specifically whether the timing chain has been inspected or replaced, particularly on cars over 100,000 miles. A specialist inspection before purchase is the safest way to know exactly what you're buying.
Every Discovery we sell is checked for known issues like this before it goes on sale, with full service history verified wherever possible.
What Causes It
Timing chain stretch is usually linked to neglected servicing — infrequent oil changes let sludge build up, accelerating wear on the chain and tensioners. It's rarely an issue on well-maintained, regularly serviced examples.
Warning Signs
A rattling noise on cold start-up, engine warning lights, or rough idling can all point to chain wear. Left unaddressed, a stretched chain can jump timing and cause serious engine damage.
What to Check When Buying
Always ask for full service history and specifically whether the timing chain has been inspected or replaced, particularly on cars over 100,000 miles. A specialist inspection before purchase is the safest way to know exactly what you're buying.
Buying from HMC
Every Discovery we sell is checked for known issues like this before it goes on sale, with full service history verified wherever possible.
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