What is the drive belt on a Subaru Forester?

The drive belt in a Subaru Forester refers to the serpentine belt—the single belt that powers the engine’s accessories such as the alternator, air conditioning compressor, and power steering pump. In newer Forester models, cam timing is managed by a timing chain rather than a belt.

What the drive belt does in a Forester

The following components are typically driven by the serpentine belt in Forester models. This belt weaves around multiple pulleys to keep essential systems running while the engine is running.

• Alternator — charges the battery and supplies electrical power to the vehicle when the engine is running.


• Power steering pump — provides hydraulic assist for easier steering, especially at low speeds.


• Air conditioning compressor — enables cooling when the A/C is engaged.


• Water pump (in some engines) — circulates coolant through the engine and radiator; in other engines, the water pump is driven by the timing chain instead.

Because the belt drives several critical systems, a worn or failing belt can lead to battery discharge, loss of steering assist, overheating, or a non-working A/C. Regular inspection helps prevent surprises on the road.

Is there a timing belt in the Forester?

Understanding the distinction between the drive belt and the timing belt is important. The serpentine belt powers accessories, while the timing belt (if present in a given engine family) synchronizes the camshafts. In most modern Subaru Forester engines, timing belts have been replaced by timing chains, which typically do not require periodic belt changes.

Modern Forester engines use a timing chain

Since around the last decade, many Forester models use a timing chain instead of a timing belt, which tends to reduce the risk of a belt-driven timing failure. However, this does not remove the need to monitor the serpentine drive belt, tensioners, and pulleys. Older Forester generations (and some specific engine variants) could have used a timing belt, so model year and engine type matter for exact maintenance needs.

Maintenance and replacement

Keeping the drive belt in good condition is essential to prevent sudden failures. The belt, along with its tensioner and idler pulleys, is typically checked during routine maintenance.

• Replacement interval: Refer to the owner’s manual for the exact interval. A typical range for many Forester models is roughly 60,000 to 100,000 miles, depending on the engine and driving conditions.


• Visual wear: Look for cracks, fraying, glazing, or missing ribs on the belt surface.


• Tension and noise: A loose belt can slip or wear quickly and may cause squealing noises; listen for unusual sounds at start-up or while driving.


• Pulley and tensioner health: Inspect the tensioner and idler pulleys for wear or seizure, since a failing tensioner can cause belt failure.


• Coordinated service: If the water pump or other belt-driven components are due for maintenance, they may be replaced concurrently with the belt in some engines.

Regular maintenance and timely replacement can prevent belt failure, which could strand you or lead to collateral issues such as electrical charging problems or overheating.

Signs of drive belt wear or failure

Be alert for warning signs that the drive belt may need service or replacement. Early detection can prevent breakdowns.

• Audible squealing, chirping, or grinding noises from the front of the engine, especially on startup or during acceleration.


• Visible cracks, fraying, glazing, or missing ribs on the belt surface.


• Battery warning light or weak electrical performance, indicating charging problems related to the alternator drive.


• Loss of power steering assist during driving, making steering heavier.


• Overheating or coolant-related issues if a belt-driven water pump is failing or slipping.

If you notice any of these signs, have a qualified technician inspect the belt, tensioner, and pulleys to determine whether replacement is needed.

Summary

The drive belt, or serpentine belt, is a single, essential belt that powers Subaru Forester accessories like the alternator, A/C compressor, and power steering pump. In newer models, timing is managed by a chain rather than a belt, reducing the risk of timing-belt issues. Regular inspection and timely replacement of the serpentine belt—per your manual—keep the vehicle running smoothly and help prevent roadside breakdowns.

When to replace a Subaru drive belt?

Generally, this replacement interval is between 50,000 and 100,000 miles.

What happens when a drive belt is worn?

A failing belt can prevent proper coolant circulation, leading to engine overheating. In severe cases, it can also cause your vehicle to stall if the alternator stops charging.

What is the most common problem with the Subaru Forester?

The most common problem with the Subaru Forester is the continuously variable transmission (CVT), which can suffer from issues like shuddering, delayed acceleration, and whining noises, and may require expensive repairs. Other frequent issues include problems with the engine (especially oil consumption), the electrical system, and, in certain model years, issues with windshields cracking and batteries dying quickly.
 
You can watch this video to learn more about Subaru Forester common problems: 51scar PROblemsYouTube · Feb 19, 2024
Transmission (CVT)

• Shuddering and jerking: This often occurs when accelerating from a stop.
• Delayed acceleration and slipping: The engine revs up but the car doesn't speed up as expected, which can be dangerous when merging.
• High-pitched whining: This can be a sign of worn pulley bearings inside the transmission.
• Repair cost: CVTs are often not rebuildable and require a complete, expensive replacement. 

Engine

• Excessive oil consumption: Many model years, particularly from the 2014-2018 generation, are known for burning through oil rapidly.
• Oil leaks: Leaks, often requiring expensive engine replacements, are another reported problem. 

Electrical and other issues

• Electrical malfunctions: Issues can range from infotainment system glitches and GPS errors to more serious problems like a battery dying prematurely or the EyeSight safety system turning off unexpectedly. 
• Air conditioning (AC): Some models experience AC failure that can be costly to fix. 
• Windshields: In the 2019-2024 generation, windshields can crack from small chips. 
• Airbag malfunctions: Older models, such as the 2009-2011, have been associated with malfunctioning airbags. 

This video explains some of the most common issues with the Subaru Forester, including the transmission and engine: 57sGear GazetteYouTube · Oct 23, 2025

What are the signs of a failing drive belt?

Symptoms of a bad drive belt include squealing or flapping noises, difficulty steering, a non-working air conditioner, engine overheating, and warning lights on the dashboard. Visually inspecting the belt for cracks, fraying, glazing, or missing chunks is also a key way to identify a problem.
 
Audible symptoms 

• Squealing or chirping: A loud, high-pitched noise, especially at startup or when turning, indicates the belt is slipping on the pulleys. 
• Whining: A whining sound that changes with engine speed can be a sign of bearing issues in the pulleys caused by a belt that is too tight. 
• Flapping or grinding: A flapping sound from the engine bay can mean the belt is loose or damaged. 

Performance and warning light symptoms

• Difficulty steering: Since the drive belt powers the power steering pump, a bad belt will make steering much harder. 
• Air conditioning failure: The AC compressor is powered by the drive belt, so it will stop working if the belt fails. 
• Engine overheating: A failing belt can prevent the water pump from circulating coolant, leading to overheating. 
• Dimming or flickering lights: The alternator's power can be affected, causing dashboard lights, headlights, or interior lights to flicker or dim. 
• Dashboard warning lights: The battery warning light or the "check engine" light may turn on. 
• Poor performance: You might notice a general loss of power or engine misfiring. 

Visual symptoms

• Cracks or fraying: Look for cracks, splits, or frayed edges on the belt. 
• Glazing: The surface of the belt can become shiny and smooth from slipping, a condition called glazing. 
• Missing chunks: Missing pieces or worn ribs on the belt are a clear sign of damage. 
• Hardened rubber: The belt may feel stiff instead of pliable, making it more likely to break.