Collect Your Data to Help The Mechanic Unravel Mystery Ailments

Dear Car Talk:

My2015 Toyota Camry makes a loud pop when I drive it. It sounds like you are opening a can. The sound is on the left rear driver’s side.

I thought it was from the gas tank. My mechanic could not figure it out. His charge was $286.

Any suggestions? -- Phyllis

Not really, Phyllis. Next letter! What I can do is give you a few tips that might help you get the problem solved.

First, I can tell you that the location of a noise is not always easy to pin down. It may sound like it’s coming from one side but may actually be a reflected noise from the other side --same with front and rear. So be open-minded about where it’s coming from. Second, try to do some more detective work yourself, which will help your mechanic figure it out. For instance, when does the noise occur? Soon after you first start out? After you’ve been driving for some period of time? At certain speeds? When the gas tank is full or half full? When you go over bumps, or take turns? Does it ever happen when the car is stopped? Information like that can really help us figure out a customer’s problem, because it helps us rule in and rule out certain things.

And you’re in a better position to collect that information than anybody else.

Third, if you have an oddball problem like this, and your mechanic can’t figure it out, the dealer is often your best bet. They work on Camrys all day, every day. So, if there’s a weird or rarely seen problem, there’s a better chance they’ve seen it before and will know what it is.

Of course, that $286 bill may seem quaint after a visit to the dealer. But if they can figure it out faster, that’ll save you money on diagnostic time.

Depending on the results of your observations, some things I might look at would be your evaporative emissions system, your rear suspension or even loose lug nuts on your wheels in case a wheel is shifting position while you’re driving and creating a “pop.”

But, start by collecting some solid data, Phyllis.

My late brother loved to say, “a problem well defined, is a problem half solved.” Then he’d go out for coffee and tell me to solve it.