By Marc Stengel

MAY 24, 1999:  Everybody knows the first rule for buying a used car, right? Have a mechanic check it out for a small fee. Well, sorry to disappoint you, but that's exactly wrong. Arranging for a mechanical check-over by a professional is Rule No. 2, and this can only follow on the heels of the correct Rule No. 1: Check out the car for yourself.

"Easy for you to say," is what you're probably thinking right about now. "Where do I start?" Even experienced do-it-yourselfers can be intimidated by the process of giving a critical once-over to a car they don't own (yet). Unlike making modifications or repairs to your own car, evaluating a prospective used car requires the combination of a doctor's bedside manner, a Sherlock's deductive intuition, and a negotiator's psychological savvy. When you're working on your own car, you can just take things apart until you figure out what's wrong. But with a used car, you're trying to detect unapparent problems (either mischievously hidden or honestly unknown) and predict what will be required to correct them.

Of course, having some mechanical ability is a good head start, but it's not absolutely mandatory. Remember, Rule No. 2 does still apply, so a mechanic should be a part of your decision-making process whatever the case. Far more important than your skill as a grease monkey, however, is your ability to conceive and follow a plan--a used-car buying plan, that is. In his 1994 book Everyone's Guide to Buying a Used Car (On the Road Press, $12.95), mechanic-turned-writer Scott Kilmer proposes a check-out procedure that is at once simple enough for the first-timer and thorough enough to identify both problems and scams.

Kilmer's book is chatty and conversational, albeit somewhat graphically challenged by today's multimedia standards. In other words, there are few pictures or charts to break up what is actually a fairly dense read; but the book is indeed chock-full o' nuggets, as if to compensate. The chapter he devotes to checking out a prospective used car is organized into three different kinds of used-car shopping strategies: 1. The Absolute Minimum Approach; 2. The Approach for Everyone Else; and 3. The Approach for Very Mechanical People.

Kilmer's middle-of-the-road plan makes logical, clever work of what might otherwise be a daunting task. Because it's impossible to predict whether you'll be looking over a car at a private seller's home or at a giant dealer lot, Kilmer starts off simply enough: "Avoid having to check out a completely warmed up car." In other words, you need to start off with a cold-starting car, and to make sure you do, Kilmer recommends some walk-around tests to perform before you crank the motor. That way, should the seller have warmed up the car ("for your convenience," he's bound to say), you can let it cool off enough to guarantee a cold start 15 or 20 minutes later. And the cold start, as we'll discover in a moment, is what reveals the cold, hard truth about much of what's going on under the hood.

Meanwhile, you've got three static checks to perform, according to Kilmer's sound advice. First, check for crash damage. Next comes a rust report. Then snoop around for flood damage. In these and all other instances, Kilmer is adamant that you take thorough notes about any- and everything that alarms or confuses you. This "diagnostic log" is, basically, your work-order-in-progress for the professional evaluation you're eventually going to get from your mechanic.

Crash damage can be both obvious and subtle. Dents and mismatched paint are bell-ringers, of course. Then there's the magnet-over-filler-paste trick. Kilmer also recommends using your fist and fingers to compare the space between the front tires and their respective sides of the body or frame. Repeat the test at the rear tires too. If there are large disparities in your measurements from side to side, a frame-twisting wreck is a likely culprit.

Rust, of course, is the automotive equivalent of cancer. If you find it, particularly if it's through-rust (as opposed to mild surface rust), your potential dream car is on the verge of becoming a nightmare. Among other tips, Kilmer suggests probing through any undercoating you may discover under the car. Although a seller may try to hide rust with a new application of this asphalt-like sealer, he hasn't eliminated the rust problem. He's only postponed it until your watch, unless you catch him at his ruse and walk away from a patched-over rust bucket.

Flood damage is literally something you have to sniff out. Mildew is the telltale culprit; and while the stuffy smell may be tolerable enough, the effects of the water that caused it can be far-reaching and serious. If you smell mildew, Kilmer recommends pulling up carpet and seat cushions. Surface rust on the floorboards is what you're looking for, but it's water damage to sensitive electronic systems that poses the greatest threat.

At this point, if all your static checks look OK, it's time to cold-start the motor. Kilmer is quite specific about what you're looking for at this point: smoke. Actually, if there's no smoke, you're in the clear (no pun intended, of course). But if smoke does appear, you need to be looking for it, so turn around in your seat and look out the rear window as best you can.

You can expect three smoky alternatives: Blue smoke indicates burning oil (and the distinct possibility that metal is grinding metal somewhere deep inside the motor). Black smoke suggests unburned fuel, caused by fuel injector or carburetor problems that may be easy to fix. Thin white smoke may just be a normal result of exhaust steam condensing in the cool outside air. But if it's warm outside, and billowing white smoke issues from the tailpipe, you can safely suspect cooling system leaks or related plumbing problems.

By itself, smoky exhaust--especially if it's minor and tapers off as the engine warms up--needn't be a deal-killer. But it's an important thing to log into your notebook, to give your mechanic a heads-up when he looks things over.

At this point, your static tests are done, and it's time to hit the road for a shakedown cruise. Kilmer's book is quite specific about what things to check over in this regard, and how. We'll continue with his road-test recommendations next time.

• Nashville Scene's What I'm Driving At Archives
• Marc Stengel Archives