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.

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, for Cars.com

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.

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.

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 he’s being overly scrutinized.

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.

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.

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.

7. Shopping around

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.

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.

9. Dog odor and other offensive smells

It’s a fact: Humans can get used to almost any strong or offensive odors. 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.