Lots of car owners come to us asking when their timing belt needs replacing. Replacement intervals will depend on the make and model of the car, with some belts lasting up to 100,000 miles.
The timing belt, often also called cambelt, is one of the most important components of your engine but also one of the most fragile ones and if they snap you could face engine damage and a major repair bill.
What Timing Belts Do
The timing belt links up the top and bottom parts of the engine. The belt matches the timing of the valves and ignition with the timing of the pistons inside the engine. What it does is keep everything in check, to ensure your engine runs smoothly.
The incorrect timing of the engine can be due to many things. Often it’s not even the belt itself. It is rather the pulleys or water pump (if on the timing belt circuit) that are damaged or that the tensioner bearing has failed.
In a worst-case scenario, your timing belt may ‘jump’. This means that the belt jumps some teeth on one of the pulleys it runs around. The timing will be off and the components inside the engine will not be aligned in the right position at the right time.
Timing Belt vs Timing Chain?
The main difference between a timing belt and a timing chain lies in their construction and materials used, as well as their method of operation. They play an important role in the synchronisation of the engine’s internal components to ensure proper valve timing and overall engine performance.
Timing Chain or Timing Belt: What’s the Difference?
Signs That Your Timing Belt Should Be Replaced
Over time the timing belt can and will wear. A squealing noise from the engine or a belt that looks frayed can indicate that your belt has worn too much. Often this is just because of normal wear, other times because of wear to parts like the pulleys or a tensioner, as a faulty pulley or tensioner can rip the timing belt.
What makes things difficult is that it’s not always clear when a replacement is needed. There may be no strange noises or visible signs of wear. If in doubt make sure to get an inspection by a mechanic who can help identify any issues.
Some signs that may indicate an issue with the cambelt:
- A squealing noise: A worn-out or damaged timing belt may produce squealing noise which can happen with belt slippage or when the belt’s teeth are worn down, causing it to not engage properly with the gears. If you hear unusual noises coming from the engine area, it’s worth getting an inspection.
- Oil leaking near timing belt: Any misplaced contaminants such as oil around the timing belt will reduce its effectiveness and accelerate its deterioration.
- Engine misfires: The car starts but stops and then likely won’t turn over when you turn the key in the ignition. Sometimes, you’ll notice that the engine will stumble and regain normal speed which could be a sign of a malfunctioning timing belt.
If you think that your belt is worn it’s very important to act quickly before it wears so much that it snaps! This may be rare but it can happen if your timing belt is not replaced timely
When To Replace The Timing Belt On Your Car
There is, unfortunately, no general set time at which point you need to replace your timing belt. The replacement interval will differ across car models, and their engines. However, usually the interval range is around 60,000 to 110,000 miles, or every four years, whichever comes first.
Car manufacturers will note when timing belts need replacing in the service schedules. Underneath you can find a table listing a number of timing belt replacement intervals on popular cars, as suggested by manufacturers.
| Make | Model | Engine | Year | Replacement interval (mileage) | Replacement interval (months) |
|---|---|---|---|---|---|
| Volkswagen | Golf | 1.6 TDI | 2008 | 140000 | 48 months |
| Audi | A4 | 2.0 TDI | 2007 | 75000 | 60 months |
| Vauxhall | Astra | 1.4 | 1998-06 | 40000 | 48 months |
| Vauxhall | Vectra | 2.0 | 1995-02 | 40000 | 48 months |
| Renault | Megane III | 1.6 | 2008 | 72000 | 72 months |
| Nissan | Qashqai / Qashqai +2 | 1.5 dCi | 2007 | 75000 | 60 months |
| Ford | Mondeo | 1.8 | 1997-00 | 80000 | 60 months |
| Peugeot | 307 | 1.4 HDi | 2001-08 | 144000 | 120 months |
| Toyota | Avensis | 2.0 D-4D | 2003-09 | 60000 | 120 months |
| Fiat | 500 | 1.2 | 2007 | 72000 | 48 months |
Make sure to always check the service schedule for your exact car model in the service book of your car, as the service interval for your model might be different from the intervals here. If you’re not entirely sure, ask your car’s manufacturer for the correct interval.
Do I need to change the timing belt every 5 years?
While the general recommendation from car manufacturers is 5 years, replacement intervals can vary depending on the specific make, model, and engine of your vehicle. For example, the recommended interval on a VW Golf is 4 years or 140,000 miles. Most manufacturers have specific guidance based on make and model – on an Audi 2009 A4, the recommendation is to inspect the timing belt at 75,000 miles and replace it at 90,000 miles. Most Mercedes-Benz cars have timing chains and the recommended replacement interval is every 80,000-100,000 miles.
Having said that, this number is a recommendation and can differ based on car usage and external conditions, too. It’s important to carry out regular inspections to check for wear and tear. If you carry out annual servicing and maintenance, any early signs of issues with timing belts or chains are generally picked up by a mechanic.
What happens if the timing belt snaps?
If the timing belt or cambelt snaps while driving, it could be very dangerous:
- The pistons can collide with the valves and damage the piston crown
- It can also cause severe damage to the cylinder head and valve guides
- Cause engine shutdown which can result in sudden and unexpected loss of power
Considering the extensive damage caused by a broken timing belt, it’s best to address any unusual changes in engine performance or strange noises as soon as possible. You don’t want to be stranded in the middle of the road compromising your safety, let alone the costly repairs!
What happens if I don’t replace my timing belt?
On most modern engines, incorrect timing or a snapped timing belt can lead to catastrophic engine damage. In so-called ‘interference engines’, it will mean that the pistons and valves will hit one another. This might not seem critical, but remember that the parts will break or bend if the parts hit each other at a high speed. If that happens an expensive engine rebuild will most likely be required.
On a ‘non-interference’ engine (usually older engines now) timing that is off is less of a problem. The internal components of the engine will not come into contact if the timing is not correct. Even if the belt breaks when you’re driving it is unlikely that it will cause any major damage to your engine, but you will find that the vehicle will not start.
Keep in mind that these reasons are exactly why a periodic replacement is needed. Issues will only show when it’s too late. With timing belts, it’s, therefore, all about prevention. That’s why manufacturers recommend periodically replacing the timing belt. That way you can reduce the chance that your belt snaps.
Service intervals are a firm indicator when you need to replace your timing belt. Remember that timing belts may wear prematurely and may need replacing at an earlier time. If you think this is the case then make sure to ask for help from an expert, as it is not worth taking risks with timing belts.
If your car needs a timing belt replacement, then we recommend having the water pump changed as well. Read more in our article about why you should change the water pump and timing belt at the same time.