Cars and trucks have changed a lot over the last 10 years. These days, almost every mechanical system is controlled by electronics. In fact, a typical two- or three-year-old vehicle has more than 100 microprocessors, 50 electronic control units and 5 miles of wiring. If you think you can thoroughly check out a late-model vehicle by taking it for a short spin and kicking the tires, think again. Finding a reliable used vehicle works best as a three-step process that involves online research, a thorough initial inspection, and a final physical and computerized inspection performed by a mechanic. We’ll give you some tips on handling the first two steps yourself so you can weed out the clunkers before spending money for your mechanic to do a final check. But trust us: If you skip the final mechanic’s inspection, it could cost you dearly. So if you have your heart set on a particular make and model, start with Step 1 before you go shopping.
Check out Vehicle Reliability
Some makes, models, engines and transmissions are known for their high failure rates. Those are the facts you want to know before you start shopping. Some of the following sources charge a fee but may also be available for free at your local public library.
Do your own Inspection
Once you’ve selected a particular make and model and you go check out actual cars, here is a series of simple, quick things you can check out to eliminate possible problem cars. Check all the features Test every vehicle feature to check for proper operation: power windows, power locks, power sliding door and hatch, sunroof, power seat, heated seats, power mirrors, cruise control, all climate control settings, backup camera and sensors, keyless entry and remote start, and exterior/interior lights.
Assemble a Car Inspection Toolbox
Before you check out a vehicle, go to the auto parts store and buy a tread depth gauge, brake test strips and a digital volt ohm meter. You’ll also need a kitchen thermometer and a flashlight. Then go through all the following inspection steps on your own car so you know what you’re doing when you conduct a real inspection on a prospective purchase.
Do a Bulb Check
Turn the key to the On position but don’t start the vehicle. All the warning lights (icons) should illuminate to prove that the bulbs work. Consult the owner’s manual to see which warning lights are installed on that vehicle. The most common is the “Check Engine” or “Service Engine Soon” light. But also check for ABS, Brake, SRS (airbag), TPMS (tire pressure), OIL, HOT (or gauge), ESP/TCS (traction/stability), and Battery/Charging lights. Then start the engine. All warning lights should turn off. If not, there’s a problem.
Check Tire Tread Depth
Using a tread depth gauge (not a penny), measure the tread depth in the center and both edges on each tire. The three tread depth readings on each tire should be within 1/32 in. of each other. A greater difference indicates an alignment, inflation or suspension problem. All four tires should be within 2/32 in. of one another. A greater difference indicates lack of proper tire rotation. Tires with a tread depth of 4/32 in. or less should be replaced (factor the cost of new tires into your offer).
Check the Dipstick
Pull the engine oil dipstick and examine the color. A honey color is an indication of fresh oil—light brown indicates slightly used oil (both good signs). However, a chocolate milk color is a bad sign that may indicate a leaking head gasket—easily a $1,500- plus repair.
Check Engine Coolant for Electrolysis
On a cool engine, remove the radiator or overflow tank cap. Using a digital volt ohm meter, set the dial to the 2-volt DC scale. Then touch the negative meter lead to the negative battery post. Dip the positive lead directly into the coolant in the radiator or overflow tank. The reading should be less than 0.300 volts. If it’s not, the coolant is worn out and there’s a good chance corrosion has already started to eat away at cooling system components. If the reading is below 0.300 volts, turn off all electrical accessories, start the engine and rev it to 2,000 rpm and repeat the test. If the reading rises, the vehicle has an electrical grounding problem that must be addressed. Wipe off the meter probes before storing.