What is an alternator belt or drive belt?

An alternator belt is known by many names including the drive belt, fan belt, v-belt or a serpentine belt.

Made of rubber, the belt is prone to deterioration over time, and due to its position next to the engine, excessive heat and general wear will lead to a brittle drive belt that is prone to cracking.

How long should an alternator belt last?

A simple rule of thumb for the lifespan of an alternator belt is around 3–4 years.

It should be inspected at your vehicle service or whenever you have an oil change.

What does an alternator belt do?

The alternator belt’s job, or drive belt, is to transfer power from the engine crankshaft to various other components; these include the alternator (of course), the air conditioning and the power steering.

Older cars had a selection of belts to take care of these tasks, but modern cars need only one. It’s an essential part of the healthy running of your engine, so it’s imperative it’s in good condition.

In many cars, the alternator or drive belt will drive the car’s water pump and oil pump, and if these are left to fail or malfunction, it can lead to severe or fatal engine damage.

Severe engine damage can mean the end of your car’s useful life, or raise some of the most substantial costs associated with vehicle repair.

What is an alternator belt tensioner and how does this work with the alternator belt?

The belt tensioner is responsible for the tight fit of your alternator belt. If it doesn’t fit correctly, there’s a danger of it slipping and failing to perform properly.

The tensioner is a small pulley that applies pressure to the outer of the belt, ensuring smooth, reliable and consistent running.

The drive belt tensioner can be infiltrated and affected by dirt gathered from an old belt or by being thrown up from the road.

If given a chance, this dirt can penetrate the tensioner and cause it to seize—becoming ineffective and leading to unwanted damage to your engine.

What does an alternator belt replacement cost?

Typically, an alternator belt replacement cost in the UK will be around £100–£200 from a registered dealer. Other garages will charge less for a new alternator belt with prices often at around half the dealer rate.

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We’re proud to say our Fixter rates to replace a worn, damaged or snapped alternator belt, are some of the most competitive you’ll find and start from £156. Simply enter your details to find out just how much you can save when you choose Fixter.

When should I change my alternator belt?

There are a few obvious telltale signs that your alternator belt isn’t doing its job correctly.

You hear unusual noises from your engine

  • If you hear a squeaking sound from under the bonnet when you start your engine, or if there is a high-pitched squeak while the engine is running, there’s a good chance this is the belt slipping, and it’s a must that you replace it as soon as possible.

You can see the visual clues associated with wear and damage

  • Any fraying, cracking or loose play in any of your engine’s rubber belts should alert you to poor conditioned parts that will inevitably lead to mechanical problems.
  • If the belt wobbles or moves excessively when the car engine is running, then it’s usually because the tensioner spring is weak or damaged. A faulty tensioner will result in additional wear to your alternator belt, shortening its lifespan and lead to severe damage and escalating costs.

Other signs that could point to alternator belt issues

  • If your car stalls regularly, or the engine refuses to turn over, it could be down to a slipping or broken alternator belt.
  • If any of the vehicle’s accessories cease to function or the headlights and interior lights flicker or operate much dimmer than usual, then this could be down to the alternator or its drive belt too.
  • If you feel your car’s steering is heavier than normal, this could be due to a lack of power transferred to the power-steering system, and could also be down to the improper performance of your alternator belt.
  • If your engine temperature warning light or battery warning light is illuminated, then it’s a sure sign of a fault that needs attention. Both of these can be related to alternator belt malfunctions so don’t take any chances and check them out immediately.

Don’t take any risks with a faulty alternator belt

Your alternator belt might not look like one of the most important components of your engine’s operation, but the role of every car’s drive belt is, as previously mentioned, paramount to the healthy performance of your car’s engine.

Failure to spot when it’s on its way out or not quite performing up to scratch can ultimately lead to a seized engine brought on by a failed water pump or another integral part of the system.

Regular care of this simple component can save the excessive costs associated with engine repair or replacement—and both are likely results from choosing to ignore a simple part of your regular car maintenance care and observation.

About Fixter

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.