7 car-buying mistakes to avoid

Modern cars have excellent rust protection, however the underbody can hide secrets. I once purchased a five year-old vehicle over the phone, not realising it had spent its life parked close to a beach. Likewise, a seemingly tidy ute from a farmer had a rust hole in the driver’s floor.

In both cases, corrosion and delamination exceeded NZTA WOF limits, with the cost of repairs estimated in the thousands. It was off to the wrecker for these two and a painful lesson for me.

This is a common trap that I fell into too many times: dodgy repairs including panel gaps that don’t line up and overuse of body filler (bog). In some cases, sellers chose to circumvent the insurance claim process by using unqualified repairers. I have even seen two different car bodies seam welded together to make one!

It went like this: I bought a car, everything seemed in order, then twenty minutes later the dashboard lit up like a Christmas tree in a frenzy of warning lights. Unscrupulous sellers can clear these lights with diagnostic equipment and some lights don’t reappear immediately, like the engine light that comes on after the engine reaches normal operating temperature. 

In these situations fixes can be costly. One European vehicle seemed like a steal… until the dreaded engine light turned on after I'd driven a short distance. It ended up being cylinder misfire that cost $15,000 to repair!

The transmission is the mechanical mischief maker, practiced in the art of deception. Constant Variable, Dual Clutch, Wet Clutch or Conventional, they all have hundreds of moving parts and plenty of ways to cause pain. Problems arise within the engineering complexity making it difficult to accurately diagnose the cause.

Gear flaring and slippage can be intermittent, here one day, gone the next. Also, some transmissions are built using plastic components. When these parts deteriorate it is typically a complete failure, with repairs costing upwards of $7,000. 

I love a nice water feature, but preferably not inside an automobile. The spare tyre well is aptly named as it often collects a pond of rusty liquid. Perished door seals or poor accident repairs causing gaps are usually the culprits. Another unamusing discovery was a leaking heater core, the only fix being to completely remove the dashboard and replace all of the carpet at an eye-watering cost.

The wiring loom (cable harness) is the car's nervous system. Miles of cables, circuits, fuse boxes and computers are interconnected. I have completely removed a vehicle’s interior down to a bare shell chasing some obscure grounding issue. Believe me, it is not a fun job! 

In one instance, rats had chewed through under-bonnet wiring, causing electrical shorting issues. This was yet another serving of humble pie, followed by a trip to the auto wrecker to accept whatever they offered.

Have you ever heard a mystery clunk while driving a car, but when you take it to your mechanic it disappears? The same principle applied to many of my purchases: no noises on the test drive, but pots and pans clanging from dark recesses the very next day. 

The worst example was a suspicious rattle I was convinced was a noisy alternator bearing. Another blunder! The actual issue was an engine main bearing, located deep inside, and the only solution was a complete engine replacement.