Knowledge base · Buying
Buying a used car: what a mechanic really looks at
A car sells itself in photos: polished, nice wheels, "just had a major service". What you don't see is underneath the car and inside the control units' memory. This is the order in which we assess a car before anyone signs.
1. Paperwork first
Does the registration match the car, is the odometer reading consistent with the history, and when does the APK expire? You can look that up free with the APK check on our homepage. An APK expiring next month is not a problem — it is negotiating room. No transfer code or no indemnity certificate from the seller is a problem; see transfer of ownership.
2. The underside — this is where the money is
On the lift we see within minutes what photos never show: rust on the floor pan and chassis rails, corroded brake lines, leaking shock absorbers, oil and coolant traces, and the state of the exhaust. Corrosion on load-bearing parts is not only an APK rejection point, it is also the repair most people underestimate.
3. Play and noise
With the car raised we check ball joints, control arm bushes, track rod ends, anti-roll bar links and wheel bearings. You often won't feel play on a test drive, but you will hear it six months later as rattling over speed bumps.
4. Diagnostics — the memory lies less than the seller
We read out the control units. Not just current faults, but stored and intermittent ones: an airbag fault that was cleared, an EGR error that keeps returning, a misfire on cylinder 3. That tells you what has been going on. What a readout does and does not see is explained in computer diagnostics explained.
5. Engine, cooling and oil
A cold start matters — don't let the seller warm the engine up beforehand. Then: exhaust colour, noise at idle, oil on the dipstick, mayonnaise under the oil cap, colour and level of the coolant. On automatics we watch shift behaviour and how it responds when pulling away cold.
6. A test drive with a purpose
Not around the block, but a stretch of motorway and a few speed bumps: vibration under braking, pulling to one side, noises in corners, air-con and cruise control, and whether the car tracks straight.
What you can check yourself
- See whether the car is cold when you arrive — a warm engine hides a difficult start.
- Feel under the boot mats for damp.
- Look at the spot where the car was parked: any drips?
- Ask for service invoices. Timing belt and clutch are the expensive items.
- Uneven tyre wear? Then something is off with alignment or suspension.
Our pre-purchase check
We assess the car on the lift, read out the control units and tell you honestly what you are buying — including what is coming up within a year. Get in touch before you arrange to meet the seller, so we can plan when the car can come by.
A complaint like this belongs with brand-specific diagnostics in Tilburg, not a plain OBD scan.