External body
Look for what a mechanic does when buying a used car or truck.
The mechanic will look for signs of rust/corrosion on the body or signs that the car has been in an accident. He will check if the car has an inspection sticker displayed if the state requires it. He will look up the VIN (Vehicle Identification Number) report. This report will say if the car has ever had an engine change, suffered flood damage or a rolled-back odometer etc.
He will also look at scratches, dents, cracks and uniformity of color of the paint. Differences in shade will show that a part has been replaced. The edges of the body should be straight without ripples or lines. The gaps between the body panels should be equal down the whole length. Hinges should not have excessive free play and the body can be checked with a magnet, which will indicate if any rust has been replaced with filler.
Fluids
Another area your mechanic will look at is if the car has any leaks from the radiator, oil or fuel tank. He will have a look at the quality of the oil and the clarity of the transmission fluid. He will be able to tell, or may even ask the owner, when the last oil change took place and if the car has been serviced regularly.
Tires
The tire treads should be in reasonable condition and equal on all four tires. They need to be replaced if they are less than 2/32of an inch or 1.5 mm deep. Is the brand of tires well known? There should be no cuts, cracks or bubbles. Also, an irregular wear pattern usually indicates some trouble with the car’s alignment or suspension.
Gauges and Electronics
The mechanic will have a look at the gauges on the dashboard. There should be no persistent warning light pointing to oil, engine, airbag or ABS trouble. He will also try all the locks, alarm, stereo, sun roof, ignition, wipers, lights and power windows. It is well worth checking all these features as they may be expensive to fix or replace. Heater and air conditioning are also looked at. The vehicle manufacturer’s label situated on the driver’s door or door jamb will show if the year of manufacture matches what the seller has claimed and if there has been any tampering.
Engine and Transmission
The engine should run smoothly without strange noises or knocking. The transmission should shift smoothly and without grinding noises. The mechanic will check clutch performance in a manual transmission and will check automatic transmission for delays, jerks or shudders.