Timing chain replacement cost.

Expect £450–£1,300 fitted at a UK independent garage in 2026 for a typical job. Engine-by-engine bands run from about £500 for a Peugeot 1.6 to £1,900 for a BMW N20, and the table above gives each one. Where the chain sits at the gearbox end or the engine has to come out — BMW N47 diesels, JLR 2.0 Ingenium — the same job runs £950–£3,000 depending on the engine and takes anything from one to four days. Main dealers charge more for the same job, and on rear-chain BMWs and Ingeniums an independent specialist who does them weekly is the cheaper route by a wide margin.

A metallic rattle for the first one to four seconds of a cold start that fades as oil pressure builds is the classic early sign. As wear progresses the rattle lasts longer, the engine cranks for longer before it catches, the idle turns rough and fuel economy drops. The engine warning light usually follows with crankshaft and camshaft correlation codes such as P0016 or P0017. Metal particles in the oil at a service mean the guides are breaking up.

A brief cold-start rattle that clears in a second or two is a book-it-this-week fault, not a stop-now one — but book it, because the rattle only gets longer. A rattle that continues after start-up, a rough or misfiring engine, or timing fault codes on the dash mean the chain has stretched or jumped. At that point stop and have the car recovered. On an interference engine the next step is the pistons meeting the valves, and the bill rises from a chain to an engine.

No. Unlike a cambelt, a chain has no scheduled interval and on most engines it lasts the life of the car. The exceptions are engines with a weak tensioner or plastic guides, where UK failures are reported from 50,000 to 100,000 miles. Oil is what keeps a chain alive: the tensioner runs on oil pressure and the guides wear fastest in dirty oil, so shorter oil-change intervals are the cheapest timing chain insurance. Trade advice for the BMW N47 is to replace at 100,000 miles or ten years, whichever comes first.

Because the chain is at the back of the engine, behind the flywheel. On most cars the gearbox has to come off to reach it, and some garages take the whole engine out, so the job is 12–20+ hours against 4–8 for a front chain. UK specialists quote £950–£2,300 for a preventative replacement with all chains, tensioners and guides; a BMW main dealer is £2,500–£4,000. Left until the chain fails, the bill starts at £1,700–£3,500 and a rebuilt or used engine is £4,000–£6,000.

The ones UK specialists see most are the BMW N47 2.0 diesel (2007–2014, worst builds 2007 to early 2009), the BMW N20 2.0 turbo petrol built 2011–2015 with faulty plastic guides, the Mini 1.6 turbo Prince N14 and N18, the same 1.6 in Peugeot and Citroën as the EP6, the Nissan 1.2 DIG-T in the 2014–2018 Qashqai and Juke and the 2015–2018 Pulsar, the Vauxhall 1.2 and 1.4 petrols in the Corsa C, D and E, the Mercedes M271 Kompressor and M270/M274 turbos, and the JLR 2.0 Ingenium diesel from 2015. Details for each are in the table above.

On an interference engine the pistons hit the open valves. At best that is bent valves and a chain, which UK sources put at £1,200–£2,700; at worst it is a damaged head and pistons too, and a reconditioned engine fitted at £2,500–£6,000 becomes the sensible route. That figure can be 60–80% of an older car's value, which is the point at which writing the car off is a legitimate answer. It is also why a cold-start rattle is worth acting on the week you first hear it.

Sometimes, and it is cheap when it works: one UK estimator lists tensioner-only at £250–£500 where the tensioner is accessible. Most garages will steer you to the full kit instead, because the chain, guides and tensioner wear together and a new tensioner on a stretched chain buys months, not years. The tensioner and guides themselves are only £150–£400 in parts, so once the cover is off the saving from leaving the chain in is small.