How much does a timing chain replacement cost?
A timing chain replacement in the UK typically costs £750 to £1,000, with RAC manufacturer averages running from about £569 on a Volvo to £1,232 on a BMW. Bumper quotes a wider £900 to £2,000 once premium and complex engines are included, which is roughly twice what a cambelt costs. The figure that decides your bill is not the badge, it is where the chain sits. A chain at the front of the engine is a long day of work. A chain at the back, as on BMW N47 and N57 diesels, needs the gearbox or the engine out, and that is where quotes climb past £2,000. Ask which one your engine has before you compare a single price.
A timing chain is the one part of your engine that nobody ever tells you to replace. A cambelt has a date and a mileage printed in the service schedule, so it arrives as a planned bill. A chain has neither, because it was designed to last as long as the engine, and for most drivers it does. That is exactly why a chain problem lands so badly. There is no diary entry, no reminder, and the first anyone knows about it is a rattle on a cold morning and a quote that can read anywhere from £750 to well past £3,000 for what sounds like the same job.
Those quotes are not a scam. They are describing genuinely different pieces of work. This guide sets out what a timing chain replacement really costs in the UK, the one question that decides which end of the price range you are in, and how to tell the difference between a noise you should book in next week and one that means you stop driving today.
How much does a timing chain replacement cost?
A timing chain replacement in the UK typically costs £750 to £1,000, according to RAC figures drawn from its approved garage network. Bumper quotes a wider £900 to £2,000, because its range folds in premium badges and the more complex engines. Both are right. They are sampling different mixes of cars.
For context, the same sources put a cambelt replacement at £300 to £700. A chain job is roughly twice a belt job, and occasionally far more, because the chain lives inside the engine rather than behind a plastic cover on the outside of it.
| What you are having done | Typical total cost | Why |
|---|---|---|
| Front mounted chain, mainstream car | £750 to £1,500 | Reached from the front of the engine, roughly 8 to 12 hours |
| Front mounted chain, premium or larger engine | £1,200 to £2,000 | More to strip, dearer kit, longer book time |
| Rear mounted chain, gearbox out | £2,000 to £3,000 | The gearbox has to come off before the job even starts |
| Rear mounted chain, engine out | £2,500 and up | Engine lifted from the car, 14 to 20 hours is common |
| Chain has already jumped and bent valves | £3,000 to engine replacement | Cylinder head repair or a replacement engine |
Why two garages quote so differently for the same job
This is the part worth understanding before you ring round, because it will save you from dismissing an honest quote as a rip off.
On most engines the timing chain sits at the front, behind a cover you can reach once the ancillary belts, pulleys and sometimes an engine mount are out of the way. It is a long job, commonly 8 to 12 hours, but it is a job a good independent can do with the engine in the car.
On a significant minority of engines the chain sits at the back, sandwiched between the engine and the gearbox. the BMW N47 and N57 diesels are the best known examples, and they are the reason the phrase "engine out timing chain" exists. To reach the chain, the gearbox has to come off, or the whole engine has to come out of the car. That adds hours before any timing work begins, and it is why a BMW 1 Series and a Ford Focus can be quoted £1,800 apart for a part that costs a similar amount over the counter.
So the single most useful question you can ask, before you compare one penny of any quote, is this: is the timing chain on my engine at the front or the back? Any competent garage can answer it from your registration in under a minute. Two quotes are only comparable once you know they are describing the same access job.
Timing chain cost by manufacturer
The RAC publishes average timing chain prices by badge, sourced from WhoCanFixMyCar quote data. They are useful as a sense check rather than a promise, because an average across a whole marque hides the front and rear chain split described above.
| Make | RAC average |
|---|---|
| Volvo | £569 |
| Peugeot | £746 |
| Citroen | £747 |
| Ford | £770 |
| Volkswagen | £779 |
| Nissan | £859 |
| Vauxhall | £877 |
| Renault | £895 |
| Toyota | £941 |
| MINI | £1,012 |
| Mercedes | £1,118 |
| Audi | £1,159 |
| BMW | £1,232 |
Notice the spread is about £660 from cheapest to dearest badge. The front versus rear chain difference on a single make can be larger than that, which is the clearest sign that the badge is not what you should be pricing on.
What should be in the quote
A timing chain is never replaced on its own by a garage worth using. The chain stretches because the things around it wear, and refitting a new chain onto worn guides and a tired tensioner is how a job gets done twice. A proper quote covers:
- The chain itself, and on many engines there is more than one, with a secondary chain driving the oil pump or a second bank of cylinders.
- The tensioner, usually hydraulic and run off oil pressure. On several known problem engines the tensioner, not the chain, is the part that actually failed.
- The guides and rails, plastic parts the chain runs against. These go brittle with age and heat, and broken pieces end up in the sump.
- Sprockets, if the teeth are worn or the engine uses variable valve timing pulleys that have play in them.
- Gaskets, seals and a timing cover reseal, since the cover has to come off either way.
- Fresh oil and a filter, which is not optional. Debris from worn guides circulates in the oil, so an oil and filter change is part of the repair, not an upsell.
If a quote looks unusually cheap, check whether it is a chain and tensioner only. That is the most common reason one price undercuts the rest, and it is the version of the job most likely to come back.
Do timing chains actually need replacing?
Here is where most advice goes soft, so it is worth being precise. A timing chain has no manufacturer scheduled replacement interval in the way a cambelt does. Nobody will ever put it on your service plan. In that sense the common claim that a chain lasts the life of the engine is true, and for a well serviced car it very often is.
What that claim quietly leaves out is that a chain still wears. The RAC's own guidance holds both ideas at once, noting that chains "can remain in top working order throughout the lifespan of a vehicle" while also saying they normally need replacing somewhere between 80,000 and 120,000 miles. That is not a contradiction so much as a description of two different cars. A chain in an engine that has had its oil changed on time can outlast everything around it. A chain in an engine that has missed services is a wear item on a clock nobody is watching.
The practical position: treat a chain as condition based, not interval based. You are not booking it on a date. You are listening for it, and you are protecting it with servicing on time.
The symptoms, and the one you must not ignore
A chain almost always warns you before it fails. The warning is just easy to explain away.
| What you notice | What it usually means | What to do |
|---|---|---|
| Metallic rattle for 1 to 3 seconds on cold start, then silence | Chain slack, tensioner not yet pressurised. The classic early sign | Book a diagnosis in the next week or two |
| Rattle on every start, lasting longer over time | Wear progressing, guides likely breaking up | Book now, before it becomes a jumped chain |
| Rattle or whine that continues while driving | Significant slack or a failing tensioner | Stop using the car and get it looked at |
| Engine management light with timing or camshaft correlation codes | Chain has stretched far enough to shift valve timing | Stop driving |
| Rough running, misfire, loss of power | Timing is out across cylinders | Stop driving |
| Metal flakes or plastic fragments on the oil filter or sump plug | Guides and chain wearing hard | Stop driving |
The cold start rattle is the one that matters, because it is the cheapest moment in the whole story. A brief rattle that disappears as oil pressure builds is the chain telling you it has gone slack. Left alone it does not recover. If you also have a lit engine management light, or the noise has changed character, treat it as urgent rather than annoying. Our guide to engine noises and what they mean covers how to tell a chain rattle apart from the other things an engine does.
What happens if a timing chain jumps
The chain keeps the crankshaft and the camshafts turning in step, which is what stops the valves and the pistons occupying the same space. If a worn chain jumps a tooth on its sprocket, that agreement breaks.
On an interference engine, which is most modern engines, the pistons then strike the valves. Valves bend, and in a bad case the piston crowns and the cylinder head are damaged too. At that point you are no longer buying a timing chain. You are buying a cylinder head rebuild, a head gasket job on top, or a replacement engine, and on an older car that is usually more than the car is worth.
This is the whole economic argument for acting on the rattle. A £1,000 job done on a Tuesday of your choosing is a different thing from a £3,500 one done on the hard shoulder.
Will a timing chain fail the MOT?
No, not directly. The MOT does not inspect the timing chain, and the DVSA MOT inspection manual contains no check for chain wear, chain noise or engine timing. A tester does not take a timing cover off, and the car MOT reads no stored fault codes.
There is one indirect route, and it catches people out. If a stretched chain has shifted valve timing far enough to log a fault, the engine management lamp lights, and the manual treats "engine MIL inoperative or indicating a malfunction" as a major defect. A major defect is a fail. So a chain problem will not be found at an MOT, but the warning light it causes will end the test, and this is one of the reasons a pre MOT check is worth the money on an older car.
Separately, the Highway Code's vehicle maintenance guidance puts the duty to keep a car in roadworthy condition on the driver, not on the annual test. An engine making a mechanical noise you have chosen to ignore is not a thing the MOT certificate covers you for.
How to make a timing chain last
Almost everything that kills a chain early comes back to oil, which is good news, because oil is the cheapest thing on the invoice.
- Change the oil on schedule, or sooner. The chain runs in engine oil and its tensioner is pressurised by that oil. Old, thin, sludgy oil accelerates chain and guide wear and slows the tensioner on start up, which is the rattle. Long life service intervals on short urban journeys are unkind to chains. What is included in a full service sets out what you should be getting.
- Use the correct grade and specification. Not just the viscosity but the manufacturer approval printed in the handbook. Chain tensioners are designed around a specific oil.
- Check the level between services. A chain that has run low on oil, even briefly, has had a bad day. Checking your engine oil takes two minutes.
- Do not ignore short rattles. They are the free warning.
- Buy carefully. On a used car, a full service history matters more on a chain engine than almost anywhere else, because the chain is the part that records how the car was treated.
How to compare quotes without getting stung
Timing chain work is high value, hard to inspect and easy to under specify, which is the combination that produces both honest wide variation and the occasional bad actor. A few questions separate them.
- Is the chain at the front or the rear on this engine? Ask every garage. If two answers differ, one of them has not looked it up.
- How many hours are you quoting, and at what rate? Labour is the bulk of the bill, so this is the number that explains the total.
- Does the price include the tensioner, guides and sprockets, or the chain alone?
- Is oil, filter and a timing cover reseal included?
- What is the warranty on parts and labour? Get it in writing.
- Genuine, original equipment or aftermarket kit? On known problem engines the uprated kit is often the one to have.
A good independent specialist will frequently beat a main dealer substantially on a job this labour heavy, and on the engines with a reputation for chain trouble the independents who see them weekly often know the job better. Our guides on questions to ask a garage before booking and the signs a garage is overcharging you are worth five minutes before you commit to four figures.
Is it worth doing, or is the car finished?
This is a fair question when the quote approaches the value of the car, and the honest answer depends on three things.
What else is due. A £1,200 chain on a car that also needs brakes, tyres and an MOT is really a £2,000 decision. Price the whole picture.
Whether it has already jumped. A preventative chain replacement on a running engine is a known quantity. A chain that has jumped is an open ended one, because nobody knows what the valves look like until the head comes off. Ask for a compression or leak down test before authorising the full job.
The rest of the car. A tidy, well documented car with a long MOT is usually worth the repair. A car with rust and a thin history usually is not. If you are unsure, a diagnostic check first is the cheap way to find out what you are actually dealing with before committing.
The short version
Budget £750 to £1,500 if your engine has a front mounted chain, and £2,000 or more if it has a rear mounted one. Find out which you have before you compare a single quote, because that one fact moves the price more than the badge on the bonnet does. Service the car on time, use the right oil, and treat a cold start rattle as the warning it is. Done in a planned way this is an expensive but ordinary repair. Left to fail, it is usually the end of the engine.
If your car has started rattling on cold mornings, find a local independent garage and get it diagnosed while it is still the cheap version of this problem.
Key takeaways
- Expect £750 to £1,500 for a front mounted chain, and £2,000 or more when the chain sits at the back of the engine.
- The RAC puts the typical range at £750 to £1,000, with averages from about £569 on a Volvo to £1,232 on a BMW. Bumper quotes £900 to £2,000 across a wider mix of cars.
- A chain job costs roughly twice a cambelt job, because the chain lives inside the engine rather than behind a cover on the outside of it.
- Ask one question before comparing quotes: is the timing chain on my engine at the front or the rear? On rear chain engines the gearbox or the engine has to come out first.
- A timing chain has no scheduled replacement interval, which is exactly why it gets missed. Treat it as condition based, and listen for it.
- A metallic rattle for one to three seconds on cold start is the early warning and the cheapest moment to act. It does not recover on its own.
- A chain that jumps a tooth bends valves on most modern engines, turning a four figure repair into a cylinder head rebuild or a new engine.
- The MOT does not inspect the timing chain at all. It can still cost you the test, because a lit engine management light is a major defect and therefore a fail.
- Oil is the whole prevention story. On time changes with the correct manufacturer specification are what a chain needs, since the tensioner runs on oil pressure.
Frequently asked questions
How much does it cost to replace a timing chain in the UK?
Most drivers pay £750 to £1,500 when the chain is at the front of the engine, and £2,000 or more when it is at the rear and the gearbox or engine has to come out. The RAC puts the typical range at £750 to £1,000, while Bumper quotes £900 to £2,000 across a wider mix of cars. Labour is the bulk of the bill, so the hours quoted matter far more than the price of the chain.
Why is one timing chain quote twice another for the same car?
Usually because the two garages are describing different work. On most engines the chain is at the front and can be reached with the engine in the car, roughly 8 to 12 hours. On some, including BMW N47 and N57 diesels, the chain sits between the engine and the gearbox, so the gearbox has to come off or the engine has to come out before the timing work starts. Ask each garage whether your chain is front or rear mounted, and how many hours they have quoted.
Do timing chains need replacing?
There is no manufacturer scheduled interval for a timing chain, unlike a cambelt, and a well serviced chain often lasts the life of the engine. That said chains do wear, and the RAC notes they normally need replacing somewhere between 80,000 and 120,000 miles. Treat it as a condition based job rather than a date in the diary, and act on noise rather than mileage.
What does a failing timing chain sound like?
The classic sign is a metallic rattle for one to three seconds when you start the engine from cold, which then goes quiet as oil pressure builds and the tensioner takes up the slack. As wear progresses the rattle happens on every start, lasts longer, and eventually continues while driving. A rattle that carries on once the engine is running means you should stop using the car.
Can I keep driving with a rattling timing chain?
A brief cold start rattle is not an emergency, but it is a booking. A rattle that persists while driving, comes with an engine management light, or arrives alongside rough running or a loss of power, means stop driving. If the chain jumps a tooth the pistons and valves collide on most modern engines, which turns a four figure repair into a cylinder head rebuild or a replacement engine.
Will a timing chain fail an MOT?
Not directly. The MOT does not inspect the timing chain and the test reads no stored fault codes. There is one indirect route though. If chain wear has shifted the valve timing enough to log a fault, the engine management light comes on, and the inspection manual grades an engine malfunction indicator lamp that is inoperative or indicating a malfunction as a major defect, which is a fail.
Is a timing chain better than a cambelt?
Each has a trade off. A chain normally lasts far longer and has no scheduled change, so it costs nothing for most of the life of the car. A belt has a fixed interval and a predictable bill of £300 to £700. The catch is that when a chain does need doing it costs roughly twice as much, and because nobody schedules it, it is more likely to be left until it fails. Neither is maintenance free, they simply fail differently.
What makes a timing chain wear out early?
Oil, almost every time. The chain runs in engine oil and its tensioner is pressurised by oil, so missed oil changes, the wrong grade or specification, low oil level or long intervals on short urban journeys all accelerate wear on the chain, the guides and the tensioner. A few specific engines also have known weak tensioners or guides, which is worth checking before buying used.
Should I replace the tensioner and guides as well as the chain?
Yes. A chain stretches because the parts around it wear, and fitting a new chain against worn plastic guides and a tired tensioner is how the job ends up being done twice. A proper quote covers the chain or chains, the tensioner, the guides and rails, sprockets where needed, gaskets and a timing cover reseal, plus fresh oil and a filter. If one quote is much cheaper than the rest, check whether it is chain and tensioner only.
Is it worth replacing a timing chain on an older car?
It depends on what else the car needs and whether the chain has already jumped. A preventative replacement on a running engine is a known cost. A chain that has already jumped is open ended, because the valve damage is unknown until the head is off, so ask for a compression or leak down test before authorising the full job. Price the brakes, tyres and MOT that are also due, then compare the total with what the car is worth.