A timing belt is a toothed rubber belt that keeps your engine’s crankshaft and camshaft turning in sync, so the pistons and valves never collide. It’s one of those parts most drivers never think about, right up until it fails. If yours is overdue for a check or a change, this guide walks you through what it does, the signs it’s wearing out, and what you can expect to pay.
Key takeaways
- A timing belt (also called a cam belt) keeps your engine’s internal parts moving in time with each other.
- Most manufacturers recommend replacement somewhere between 100,000km and 160,000km, though this varies by make and model (a general estimate, always check your own car’s handbook for the exact figure).
- Watch out for a high-pitched ticking noise, misfires, oil leaks near the belt, or an engine that won’t start.
- Replacement typically costs somewhere in the region of €400 to €1,000, largely down to labour rather than parts (an estimate, not a quote, so check with your own garage).
- If it snaps while you’re driving, the damage is usually serious enough that many cars are written off.
What is a timing belt and what does it do?
A timing belt is a reinforced rubber belt with teeth on the inside, connecting your engine’s crankshaft and camshaft. It makes sure the valves open and close at exactly the right moment as the pistons move, so nothing inside the engine hits anything it shouldn’t. Without it working properly, your engine simply can’t run the way it’s meant to.
This matters for pretty much any petrol or diesel car with an internal combustion engine. If you’re driving a fully electric vehicle, none of this applies to you, as EVs don’t have a timing belt at all.
Timing belt vs timing chain
Timing belts and timing chains do the same job, they just use different materials. A timing belt is made from rubber reinforced with nylon or fibreglass. A timing chain is made of metal links, a bit like a bicycle chain, and tends to be more durable as a result.
You’ll find timing belts more often in modern, mass-market cars, and timing chains more often in older cars and some performance models. Neither is automatically “better”, but chains generally go longer between services, while belts are usually cheaper to replace.
Timing belt vs cam belt
There’s no difference. A timing belt and a cam belt are the exact same part. “Timing” refers to keeping the engine’s pistons working in the correct order, while “cam” refers to the belt connecting the crankshaft to the camshaft.
Which term you’ll hear tends to come down to where you are. In Ireland, “timing belt” is the more common term, while in Britain, mechanics are more likely to say “cam belt”. Your mechanic will know exactly what you mean either way.
How long does a timing belt last?
There’s no single fixed number of kilometres at which a timing belt is guaranteed to fail, so don’t be pressured into an early replacement without good reason. As a rough guide, most belts are due somewhere between 100,000km and 160,000km, though this depends heavily on the make and model of your car. This range is a general estimate rather than a manufacturer figure, so always check your own car’s handbook or logbook for the interval that applies to you.
Some belts last well beyond that. Others don’t. The safest way to know where you stand is to check your car’s service history or logbook for the last replacement date, particularly important if you’ve bought the car second-hand and can’t be sure of its full history.
Signs your timing belt needs replacing
A few warning signs are worth knowing, even if you’re not planning on doing any of the diagnosis yourself:
- A high-pitched noise from the engine. A piercing or squealing sound, especially on start-up, can point to a timing belt under strain.
- Engine misfires. If the belt has slipped or is wearing unevenly, the valve timing goes off and the engine can misfire.
- Oil leaks near the timing belt cover. Oil weakens rubber, so a leak in that area can accelerate wear.
- Visible cracking or fraying. Not every car makes this easy to check, but where you can see the belt, look for cracks, glazing, or missing teeth.
- The engine won’t start. This could be any number of things, but a snapped timing belt is one possibility, particularly on an interference engine.
If you’re due a service anyway, our top tips on getting your car serviced are worth a read, and it’s worth knowing what’s covered under AA approved servicing too.
How much does a timing belt change cost?
Pricing depends heavily on the make and model of your car, but as a rough guide, you’re typically looking at somewhere between €400 and €1,000, covering both parts and labour. Most of that cost is labour rather than the belt itself, since a mechanic usually needs to strip back several other components to reach it.
This is a general price estimate rather than a fixed quote, and actual cost will vary by garage, region, and vehicle. We’d recommend getting a couple of quotes before booking the work in.
What happens if the timing belt breaks while driving?
Don’t worry if you’re reading this after the fact and trying to work out what’s next, but a snapped timing belt while driving is a serious mechanical event. Because the belt keeps everything moving in sync, a break means the valves and pistons can collide, which typically bends or breaks internal engine parts.
In most cases, the cost of repairing that kind of damage is high enough that the car ends up written off rather than repaired. It can sometimes be worth fixing on a newer, higher-value car, but on an older vehicle it rarely makes financial sense, which is exactly why keeping on top of replacement intervals matters.
If your timing belt has broken while you’re out on the road, AA Roadside Assistance can help. If you’re broken down and not a member, call +353 1 649 7460 and we’ll get someone out to you.
FAQs
Can I still drive if I think my timing belt is worn?
It’s best not to. A worn timing belt can fail without much warning, and if it snaps mid-drive, the resulting engine damage is usually far more expensive than the replacement itself. Get it checked by a mechanic as soon as you notice any of the warning signs.
Is timing belt replacement covered by car insurance?
No. Car insurance covers accidents, theft, and certain other unexpected events, not routine wear and tear or scheduled maintenance like a timing belt change. That’s a servicing cost, not an insurance claim.
Do electric or hybrid cars have a timing belt?
Fully electric cars don’t, as they have no camshaft or crankshaft to synchronise. Most hybrids still run a petrol engine alongside the electric motor, so they typically do have a timing belt or chain that needs the same attention as a conventional car.
How do I know if my car has a timing belt or a timing chain?
Check your owner’s manual or ask your mechanic at your next service. It’ll usually be listed under the engine specifications, and your mechanic can confirm it in a couple of minutes if you’re not sure.
The bottom line
A timing belt is a small part with a big job, and it’s not something to put off once it’s due. Keep an eye on your service history, listen out for the warning signs, and get it looked at by a mechanic if anything feels off. If you’re due a service or want to know more about what’s included, check out AA approved servicing here.
