Every component that makes up a vehicle has a shelf life and is not designed to last forever. Some parts are regularly replaced as part of a maintenance service schedule, based on time or distance travelled (set by the vehicle manufacturer).

Some parts and features are subject only to a visual inspection or specialised equipment test, and if they look worn or fail the test, then a replacement is required.

Service items

The most common parts that vehicle owners are made aware of are those replaced during regular vehicle servicing. Oil, air, pollen filters, sparkplugs, oils, cam belt, driveline and cooling system fluids are all examples of this. These are mostly know as scheduled maintenance items. If you own a vehicle long enough, you could even replace all of these items a few times over.

Common small repair parts

There are times in the life of a vehicle when regular service items are joined by regular repair items, which can then morph into expense after expense, until you sell or dispose of the vehicle. They don’t have a scheduled replacement interval, but they are subject to certain conditions that can prevent them from lasting forever.

Ignition coils, lambda/exhaust sensors and steering or suspension bushes/joints are just some parts that as both technicians in a workshop and as AA Motoring Advisors we’ve seen replaced more commonly through a vehicle’s life.

Ignition coils

Ignition coils are generally made from a plastic-type material and in modern engines sit down inside the cylinder head, directly on top of the sparkplug. If you have ever removed sparkplugs on an engine that’s just been running, you will know that they can get extremely hot. Which is not recommended, we always advise motorists to wait until their engine is completely cooled down before attempting to remove a spark plug.

Because these ignition coils sit above the spark plugs, they too get extremely hot, and so naturally, over time, they’ll break down and cause a misfire. If one goes, then the chances are that the others are not too far behind.

Exhaust sensors

The same goes for the sensors in your exhaust, they read the gases before and after the catalytic converter to check emissions efficiency and are in the constant flow of the red hot exhaust, so unfortunately it is a given that they could be prone to fail at some stage without regular servicing.

Steering and suspension components provide the cushion between your tyres and the car. They take a hammering over years of travel in all sorts of conditions like extreme cold, heat and uneven surfaces like gravel dirt, rocks and tar seal. They can also be affected by age, rubber bushes can become hard over time and shrink while others can simply wear out.

Repairs that can get bigger

After a vehicle reaches around 10 years old, you’re more likely to need repairs in addition to your regular servicing. These can also lead into big ticket items like cooling systems, engines and drivelines/transmission. All of these items could, depending on the conditions they have been exposed to, start to show signs of wear, burn or leak oil or coolant, or just not perform as well as they once did. 

With some vehicle types the odds of this happening are greater, and with others they can be less of a gamble. Japanese manufactured vehicles have a reputation for being a bit more reliable and cheaper to fix as they age, which is why they are also a popular import into NZ.

The new car buyer

Think about a new car and how long a particular model stays in production for before it is upgraded. Let’s say the day you purchase it can be that ‘model year’ or the previous year’s ‘model year’ date, then in the next year or two the model will get a facelift which changes features like the lights and bumpers.

After five to seven years, this model is superseded by an all-new version of that make and model. Now the focus is on this all new model with regards to the warranty and service plan so see you through the next three to five years. For some buyers, this is a cycle that they want to be in and are more than happy to replace their five to seven year old car.

The prudent buyer

The prudent buyer is more than happy to buy a modern car that should still be reliable, but the price is now far more attractive as the depreciation has been significantly worn by the first owner.

The bargain hunter

The bargain hunters are always on the lookout for a low cost, good working order vehicle to keep them mobile. If they don’t get a Pre Purchase Inspection before they buy, they can unfortunately soon find out that there are a lot of worn out items to replace for their next Warrant of Fitness. Often they are faced with little choice but to sell the car on, or let a wrecker or scrap dealer come and collect it and take it off the road.

The rule of thumb is that the newer the car, the safer and more reliable it is for both the occupants and pedestrians. At last count in 2017, the average age of a car on our roads was 14.4 years, which is one of the highest in the world. 

How can the AA help?

• AA Auto Centre - aa.co.nz/autocentre
• AA Roadservice - aa.co.nz/roadservice

Vehicle experts you can trust