If you already know all about timing belts, the easy answer is that your timing chain does pretty much the same thing. There are, however, differences in how they work, the jobs they do, how long each lasts, and what they cost.
So, in true Fixter fashion, we’re going to look at all of those elements and clear matters up once and for all. We’re going to talk about the advantages and disadvantages of a timing chain over a belt, how long they last, how they came in and out of favour, and we’ll also look into how much to replace a timing chain.
What is a timing chain?
A timing chain is responsible for controlling your pistons and valves, making sure they operate precisely when they need to inside your engine cylinders. Four-stroke engines operate on a cycle with, yes, you guessed it, four strokes within each one.
- Intake stroke
- Compression stroke
- Power stroke
- Exhaust stroke
Throughout one cycle, your camshaft spins once, and your crankshaft spins twice. During that phase, those four separate strokes happen. This is what’s known as mechanical timing or synchronisation—or simply ‘timing’ for short.
The job of your timing chain—or belt—is to operate the precise operation of the cycle and its strokes. If the pistons and valves don’t fire or move exactly when they should, your engine won’t work, or worse, suffer severe damage.
What’s the difference between a timing belt and a timing chain?
A timing belt is a heavy-duty rubber belt, with teeth along one side that fit into a series of pulleys and cogs that control your engine timing. If you open your bonnet, you should be able to see the rubber belts, or if not, a plastic case or cover where they’re sat.
A timing chain is a heavy-duty metal chain—something that looks a lot like a bicycle chain—but if you try to spot it when you lift your bonnet, you won’t. Your timing chain works inside the engine casing as it needs lubricating (with engine oil) to keep it in good condition and to operate as it should. It also requires oil to control the tensioners that keep it nice and snug.
Why have two systems that do the same job?
In the early days of motoring, all cars were built with timing chains. During the 1960s and 70s, a replacement system (rubber timing belts) was introduced, down easier to manufacture, resilient, durable materials.
The new rubber timing belts were much quieter than chains and were a lot easier to access and replace.
However, all that glitters is not gold. The argument for chains over belts landed back on the table during the 1990s.
Today, there are plenty of manufacturers who have reverted to fitting timing chains to their vehicles as standard, and many into particular models where they feel the advantages make them the best component for the job.
Most BMWs and Mercedes cars use driving chains. Some of the bigger American and European marques including Cadillac, Chevrolet, VW and Renault use timing chains in a selection of their models. It’s not just the big power brands either; you’ll find timing chains in some popular Dacia models, the Honda Jazz, as well as in selected Fords, Citroens, Fiats, and Mazdas.
Timing chain advantages and disadvantages
- A chain offers superior strength, giving it a far longer lifespan. Hopefully, with proper care and maintenance, a timing chain should last the lifetime of your vehicle.
- Maintenance is simple—keep up with your oil changes and consider a one-off check at the 125k-mile mark.
- A metal chain is heat resistant, so isn’t vulnerable to changing conditions in the weather. A rubber belt can freeze in low temperatures, affecting performance.
- A timing chain is much heavier than a rubber timing belt. This increases fuel consumption, and in turn, affects your fuel economy, adding to pollution, and impacts engine power.
- A timing chain is far noisier than a timing belt.
- Due to the extra weight, a timing chain is often only available for use on larger engine cylinders.
- They’re considerably more expensive to replace and to work on.
- A timing chain requires constant lubrication.
How do you know if a timing chain needs replacing?
It’s tricky to know precisely when a timing chain is worn given it’s hidden within the engine casing, but there are a few ideas that could suggest it could be happening.
As the chain wears, it stretches and affects the timing. A worn chain, or its tensioners, can affect engine operation and trigger the warning light or some unusual noises. Don’t be surprised if a rattling, whirring, whining or buzzing noise emitting from your engine isn’t down to your timing chain.
If a chain is worn, your engine could become slightly more sluggish than usual, feel low on power, or it might even struggle to start.
Whenever a check-engine light illuminates on your dashboard, there’s a possibility that it could be down to your timing chain.
How much does it cost to replace a timing chain?
If they’re so robust, why are we even talking about what they cost to replace? Well, even though they’re built to last, we know that no vehicle component is invincible.
Without the correct lubrication, your chain will suffer. That means excessive wear and introducing weaknesses. If your timing chain snaps, it can kill your engine. And it doesn’t have to be the fault of the chain. Other engine components that develop faults can put enough extra strain on your chain, leading it to fail.
Changing a timing chain can take all day, even for the most experienced mechanic with all the right tools at their disposal. The extra work will add to labour charges and the total cost of your bill.
So, how much is a timing chain?
With a replacement chain costing anywhere from £50 to £150 on a typical family car, the total price can end up anywhere between £500 and £1,500. The average price is usually somewhere around £700/£800. Don’t be surprised, though, if the higher-end marques’ prices rise considerably. You could be looking at paying up to and beyond £3k for sports models and luxury vehicles.
Book a timing chain check or replacement with Fixter
If you’re concerned by some out of the ordinary noises coming from your engine or think that it could be the time to make sure everything’s behaving as it should under the hood, give us a call and book your car in today.
We save so many of our customers a great deal of money, and prevent much more severe—and far more expensive—catastrophes from happening.
Fixter is revolutionising the car maintenance industry, one repair at a time. Fixter was founded to make car maintenance as easy as booking a taxi. Digital, transparent and stress-free, with world-class customer service. Since launching in Manchester in 2017, Fixter has expanded to more than 100 cities across the UK and provided thousands of car owners with honest, convenient and affordable car repair services.