Top 10 Lousiest Things Customers Do

What's your relationship like with your mechanic? Are you grateful? Wary? Terrified? Well, remember, it's a two-way street. Your mechanic is a person, too. A person with feeling and emotions — even if they're generally expressed as grunts.

So, from a mechanic's point of view, what makes a "good" or "bad" customer? What put you in your mechanic's doghouse?

Here's our list of the Top 10 Lousiest Things Customers Do. Avoid the behaviors on this list, and you'll probably get better service. Your mechanic will work a little harder to find that hard-to-reproduce problem instead of just telling you, "It wouldn't do it for us." He may even be more inclined to actually remember to tighten up your lug nuts.

Tom and Ray Magliozzi, Click and Clack, the Tappet Brothers

P.S. Do you want to learn about the other side of the equation? Check out How to Be a Great Customer.

1. Withholding vital information

When you go to your doctor complaining of a headache, you wouldn't forget to mention that you walked into a bridge abutment a day earlier, would you? Your doctor needs all the information he can get to make an accurate and timely diagnosis.

Your mechanic is no different. He'll need to know such things as your description of the problem, when it started, what makes it worse or better, and any other signs or symptoms that something might be wrong. Spend a little time observing the problem so that you understand the conditions under which the problem occurs. And when you get there, don't withhold information for any reason, intentionally or unintentionally. It's up to your mechanic, not you, to decide if the information you're providing is relevant.

2. Blaming your mechanic for other problems

It's a little-known fact, but once a problem is repaired, it's not uncommon for customers to notice other issues. For example, you get your muffler fixed, and suddenly you notice a rattling timing chain because you can hear again! Don't jump to the conclusion that your mechanic "broke something else" when he fixed your car. Instead, ask him politely if it's possible that the new noise you're noticing is related to the repair he did.

Look at it this way: At any given moment, most cars have at least a few items that need attention. Is it possible your mechanic caused a new problem? Sure. It happens occasionally. But in our experience, it's not that common.

Rather than starting out by accusing him, approach your mechanic with respect. You'll find he's more likely to welcome your question with an open mind, rather than pretend he had a head injury earlier in the day and no longer understands English.

3. Hovering

Remember that creepy, annoyed feeling you got when your sixth-grade teacher stood over your shoulder, watching you answer questions on your geography quiz? That's exactly the way it feels to a mechanic when a customer hovers during a repair. It's distracting. And, frankly, many of us mechanics are not exactly overflowing with brain cells, so we really need to focus on the repair. In our experience, the lowest-quality work gets done when the mechanic feels as if he's being overly scrutinized.

If your repair is going to take longer than a half-hour, we suggest a leisurely walk to the nearest internet-equipped cafe. You can relax and watch cat videos on YouTube, and your mechanic can fix your car without hearing you audibly sigh every time he gets a greasy fingerprint on your battery cable.

4. Monopolizing your mechanic's time

There are certain times of day when a shop can be very busy with customers eager to drop off or pick up cars. Generally, this tends to happen between 7 and 9 a.m. and between 4 p.m. and closing. At these times, it's rude to monopolize the time with the service writer (the person at the front desk who takes your information) when nine other customers are waiting behind you.

If you're someone who asks a thousand questions, why not bring in your car after the morning rush? Your garage's service writer will have more time, won't be distracted by the antsy customers shifting from foot to foot behind you, and you won't keep those other customers from their shifts as safety supervisors at the nuclear plant.

5. Not giving your mechanic the benefit of the doubt

There's no doubt there are many disreputable characters in our business. We're among them! But quite a few mechanics are decent, trustworthy and conscientious.

Until your mechanic has proven to you that he's Bernie Madoff with a wrench, assume his innocence. That doesn't mean he won't make honest mistakes sometimes. We all do. And some problems are just hard to diagnose.

When a problem isn't fixed the first time, bring it to your mechanic's attention. Repair shops, like most businesses, rely on repeat customers and good word of mouth. It's likely your mechanic will try hard to get it right. And if you're kind about it, rather than assuming he's a crook or a dope, he'll likely try even harder to help you.

If you're worried that your mechanic might be something less than an Eagle Scout, check the garage and dealer reviews in our Mechanics Files and at Cars.com, and find a mechanic you feel you can trust.

6. Don't be a yeller

If you've ever been yelled at in public, you know it's about as embarrassing as peeing in your pants. We know, because we've been yelled at in public for peeing in our pants (though not in the last six or eight weeks, mind you).

The last thing anyone wants is to be humiliated in front of others, especially his employer, employees or other customers. If you can't control yourself, walk around the block a few times and punch your fist through some drywall.

Don't talk with your mechanic until you've regained your composure. You'll be doing him a favor, and you'll be doing yourself a favor because once you declare war by yelling, the symbiotic relationship is all but over. If you really feel that you've been treated badly or unfairly and need to raise your voice to make your point, please have the courtesy to do it in private.

7. Shopping around

Everyone is entitled to shop around for the best price on a repair, but determining an estimate takes time. A mechanic needs to check parts lists and costs online, and even make a phone call or two as well.

If you are shopping around for a second quote, our advice is to confess rather than pretend you're not. Explain the diagnosis and the estimate you've received for the repair. Ask if it sounds right, or if it could be done for less. A lot of mechanics will be grateful not to have to work up a useless quote in that case, and they will be more likely to be helpful.

If you're calling a shop you know, be polite and give them a little business from time to time. After all, you're using their skills and knowledge for free.

By the way, it's easy for us to tell when a caller is checking a quote they've already received. After all, how many customers just happen to know, for example, that they need a "vacuum-switching valve for their evap system?"

8. Getting the work done elsewhere after a diagnosis

Very few shops charge the true labor cost for the time involved in diagnosing a problem. It's more likely they're giving you a deal on the investigative part of the repair, in anticipation of being paid for the repair itself. Unless you have a good reason for it, it's rude to take your car to one place for a diagnosis, and then to a slightly cheaper place to have the car repaired.

Should you take the free or cheap diagnosis and go elsewhere? Remember this fact: Mechanics have great memories. If they work up a diagnosis on a car and the owner takes it elsewhere, and happens to bring the car back some other day, the mechanic is likely to remember the vehicle. At our shop, we'll ask why the customer took the car to another shop, so we can address any problems on our end. Have a reasonable explanation at the ready, or be prepared to be suitably embarrassed.

9. Dog odor and other offensive smells

It's a fact: Humans can get used to almost any strong or offensive odors. It's an evolutionary coping strategy that has a lot of upsides, like being able to share your house with a litter box or enjoy professional wrestling up close. If you frequently carry around wet dogs, soiled diapers or other odiferous items in your car, please realize that your mechanic might not be as accustomed to these smells as you are. Take a few minutes to clean your car of rotting food, moist dog blankets, old gym bags and other malodorous items. Then air out your car. Your mechanic will appreciate it.

10. Having unrealistic expectations

When we schedule service, we try to be clear as possible regarding how long a repair will take. And if we say it's going to take all day, we'll need all that time to get the job done. At our shop, we'll need to have your car in the shop at 8 a.m., to have it back to you at 5 p.m. So if you drop off your car at noon, don't expect us to have it ready for you at 4 p.m.

One last thought: Remember that cars are increasingly complex, and mechanics are only human — if that! Surprises are not uncommon, mistakes happen, bolts can turn out to be rusted in place, and other jobs may take sudden precedence. Give your mechanic a little breathing room. He'll appreciate it, and you'll both be happier in the end.

And if you liked the way a repair went? Brownies never go out of style.

© Cars.com 05/1/2013