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Mazda 3 BK to BL 5 most common repairs

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Updated 10 Jun 2020

Joel Ilton

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First introduced into Australia at the end of 2003 to replace the familiar but aging Mazda 323, the new BK Mazda 3 was the third model to arrive during the Mazda ‘Zoom Zoom’ marketing campaign behind the Mazda 6 and the MX-5 roadster. It took the Australian market by storm by being well priced as well as packed full of features.

It was based on the Ford C1 platform, which was shared with the Ford Focus and Volvo S40 of the time, and came in both hatch and sedan variants, with either a 2-litre or 2.3-litre engine, depending on the specification. Mazda sold 166,615 Mazda 3 models before the introduction of the BL update in November 2008.

The BL Mazda 3 was also based on the C1 platform, however Mazda decided to update the 2.3-litre engine to the 2.5-litre engine that was shared from the larger Mazda 6, and a diesel variant was introduced in 2010, although it did not sell as well as the petrol models due to only being available with a manual transmission.

In 2012, the first ‘Skyactiv’ engine was introduced featuring direct fuel injection, which reduced fuel consumption and exhaust emissions.

With the earliest Mazda 3 models reaching 16 years old and hundreds of thousands of kilometres travelled, many components fitted to these vehicles have reached the end of their operational life and may need to be replaced.

As with many other vehicles on the road, the Mazda 3 has a number of ‘common issues’ that affect both engine types and transmission variants, and using the data available to us here at AutoGuru, we have compiled a list of the 5 most common repair requests for the BK and BL models of the Mazda 3.

Note: This list does not include normal wear and tear items such as tyres and brakes or servicing costs, as these are applicable no matter which vehicle you drive. If you are interested in servicing and repair costs of the Mazda 3, you can click here.

1. Engine Mount Replacement

Many Mazda owners have complained about the relatively high wind noise and vibration that comes through the cabin on longer drives, and one of the culprits for this vibration is the engine mounts. The right-hand engine mount can fail on these models due to the way the engine delivers its power - as the engine moves, the engine mount twists slightly to absorb most of the movement, and this can wear it out over time.

Thankfully, the engine mounts aren’t too difficult to replace and revised parts have been released over the years to better combat this engine movement and return the vehicle to a comfortable state.

2. Air Conditioning Compressor Failure

Although not limited to the Mazda 3, many of the earlier models have suffered from an internal failure of the air conditioning compressor or compressor clutch failure. When this happens, warm air will blow through the vents, even with the air conditioning switched on, as the vanes inside the compressor fail to operate.

This doesn’t allow the refrigerant to flow through the system to produce the cooling effect and, most of the time, a new compressor is required to rectify the situation. Replacement of the receiver dryer will also need to be carried out with any air conditioning repairs.

The 2008 Mazda 3 Sedan

3. Alternator Replacement

The alternator is designed to provide power to the vehicle when the engine is running for accessories as well as delivering charge to the battery. Over time, the brushes in the voltage regulator wear out, and reduced charge is provided. This is more pronounced on the earlier models that have travelled more kilometres, but can also happen on newer versions.

The voltage regulator is integrated into the alternator itself, so the only option is to replace the complete alternator. Symptoms of needing an alternator replacement include a battery warning light on the dashboard and vehicle electrical systems malfunctioning.

4. Oxygen Sensor Replacement

The petrol Mazda 3 is fitted with two oxygen sensors in the exhaust - one before and one after the catalytic converter - and these are used to determine how effectively the engine and catalytic converter are operating by measuring the oxygen content of the exhaust gas. They rely on electrical voltage to warm up, and are quite sensitive to moisture and condensation that can form inside the exhaust when the vehicle is parked.

After many heat cycles, they can lose their effectiveness and will not read correctly resulting in their requiring replacement. When this occurs, a Check Engine Light will appear on the dashboard and a diagnostic trouble code will be stored inside the Engine Control Unit (ECU). These sensors are not repairable so replacement is the only option.

However, on some newer models, there was a software update available from Mazda to recalibrate these sensors, so it’s imperative correct diagnosis is carried out to prevent replacement of correctly operating parts.

5. Timing Chain and Guide Failure

All BK and BL Mazda 3 petrol and diesel models are fitted with timing chains to accurately control the valve timing. Unfortunately, many petrol models have had issues with failing timing chain plastic guides and issues with the timing chain itself. Symptoms of a failing timing chain or timing chain guide is a rattle on cold starts or at idle which can be more pronounced when driving.

The only way to rectify this issue is to replace the full timing chain kit, which can be expensive due to the labour involved. Vehicles with a poor service history are more likely to suffer from failed timing chains and guides as the system relies on oil for lubrication and tension on the chain.

The Mazda 3 was at the sharp end of the segment when many Australians were downsizing and moving away from the larger Holden and Ford models and in June 2011 the Mazda outsold both Holden and Ford, as well as its main rival, the ever popular Toyota Corolla. The Mazda has gone from strength to strength, and has continued to place in the top 5 most popular new vehicles sold in Australia.

Should you be having any trouble with your BK - BL Mazda 3, help is at hand and an Autoguru technician will be able to diagnose and provide quotes for any repairs or servicing needed to get your vehicle back on the road in no time.

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Written By

Joel Ilton

Finding a passion for cars from a young age, Joel carried out work experience as a mechanic whilst at school before starting an apprenticeship after finishing year 12.

After almost 10 years on the tools and in customer service, he moved into the IT realm as a Data Analyst and In-House mechanic at AutoGuru.