Can you bring your own car parts to a mechanic?


If you’ve ever been confronted with a large repair bill from a mechanic you may have thought supplying your own sourced parts would save you some of the expense. It’s never been easier to look online and check the latest price for car parts via Repco or Super Cheap Auto. You may even have brake pads or spark plugs hanging around the garage at home. But what are the implications to you and the mechanic by installing customer-supplied parts? We take a look. 

Will mechanics in New Zealand use your supplied parts?

We asked a bunch of the MTA-approved mechanics on My Auto Shop and found that there are mixed reviews on customer-supplied parts across New Zealand. Generally, mechanics are wary of being held legally liable for their work under the Consumers Guarantees Act (CGA) here in NZ, and refuse to use supplied parts for anything major. Occasionally they will consider installing parts that are otherwise difficult to source, or if they are unique to a specific model.

Mechanics are held legally liable for the quality of their work under NZ law. Many offer time-bound or mileage-bound guarantees that go even further than the CGA. If they install a part that turns out to be wrong it may cause other issues with the vehicle. In our experience mechanics will look to cover themselves to avoid future disputes before going ahead.

A typical repair invoice will outline the labour and parts required to complete the job. Mechanics add margin on both their labour cost and on parts, much like builders or plumbers do. You may well find mechanics will increase their labour rate in order to offset the lost parts margin when they agree to use your parts.

Fit and fitment

Another consideration is that there are literally millions of different car parts, and it’s often difficult to ensure you buy the exact parts to fit your car’s make and model. Mechanics have access to tools that make fitment easier, and most source their parts from a range of parts suppliers and manufacturers. A mechanic’s experience in sourcing the right parts ensures the correct part is ordered.

What’s the difference between OEM and Aftermarket car parts?

The NZ car parts market is made up of two types of parts: OEM and Aftermarket. OEM stands for “original equipment manufacturer” and refers to parts made by the car manufacturer. If you replace your Toyota Corolla suspension with Genuine Toyota parts they are OEM parts. Any other generic parts are considered Aftermarket. There is nothing wrong with using Aftermarket parts, but its worth considering they are usually made for a range of vehicles, and therefore getting them to fit maybe a little harder. 

Is there a guarantee or warranty for car parts I buy?

Parts supplied by a customer may have a warranty with the supplier but it’s unlikely the mechanic will guarantee it. It can be difficult to know if a part has failed due to it being faulty or having been installed incorrectly. This can lead to a “he said, she said” situation and a standoff. An experienced, MTA-approved mechanic will stand by the parts they install into your car, confident they have sourced them from a reputable wholesaler, and that they are quality parts.

Sourcing parts isn’t always easy anyway

While some basic parts can be easily matched to your car and found online, many more complicated parts are actually really difficult to source. You may find you save a few bucks in the short term, but come to regret supplying generic parts if that part fails in the future.

We highly recommend finding a reputable mechanic and trusting them to source the correct parts for your car. We work with hundreds of mechanics, all MTA approved, as they set the standard for quality workmanship and parts in NZ.