I miss the sound my 5-year-old son and I used to make when driving toy cars. It involved sticking out our tongues and, for the most part, spitting. The other day, my boy came to me with two cars in his hands, one for him and one for me. He asked if we could race around the living room like old times. I told him we couldn't. He was sad. I was sad, too.

My son and I used to love playing cars together. We'd race our vehicles up and down the Pergo floors, have shoot-'em-up car chases in his bedroom and go fourwheeling on the couches, all while making that hot-rod sound that we made: thp-thp-thp-thp-thp.

It was a funny sound. On one hand, it sounded tough and fast—thpthp-thp-thp-thp. On the other hand, it sounded like an old beater car with a busted muffler and only running on half its cylinders—thpthpthpthpthp. The louder we made the sound, the faster our cars went. And the louder we made the sound, the more we'd laugh. It was something we enjoyed doing together.

And now it's gone.

Thinking back over the years, my son and I really had the best of times making that hot-rod sound while playing cars. Nothing compared to it. We could make the sound for hours, and we usually did, oftentimes resulting in numb tongues and chapped lips. But to give up making the noise for such petty reasons would be like an Olympian giving up his sport because of body soreness after an event.

"No, no," I said to my son when he offered up the toy car to race. "We can't do that anymore. In fact, maybe it's best we get rid of the cars."

My son handed over the two toys, his chin buried deep in his chest. He couldn't protest. He knew what needed to be done. After all, what good were toy cars if you couldn't make the accompanying hot-rod sound while moving the vehicles along the carpet? My son and I would have to think of a new activity to enjoy together.

I suggested playing board games. We were both optimistic about the idea, but let's face it, there's nothing fast or loud about Candy Land or Connect Four. The two of us sat in silence, trying to make the best of what he had.

My wife noticed my son's long face. And she noticed mine, too.

"You'll be okay in time," she said to me.

"No," I replied, "it'll never be the same for me."

My wife looked across the room at our son. She scanned his face for any indication that joy would return to his life.

"It'll never be the same for him either," I said.

"He'll be fine."

"You don't understand," I said. "People like that have something inside. Something to do with death."

"Death?" my wife asked. "Death of what? A spitting sound?"

"If that kid smiles the same ever again, he'll pack his bags and be on his way."

My wife looked confused.

My boy smiled, went into his room, grabbed a backpack with underwear for two days, a box of crayons and his favorite teddy bear—everything he'd ever need. He came out, smiled and then said, "Now I gotta go."

My wife gasped.

He walked out of the house.

"I gotta go, too," I said. I followed.

Two weeks ago, my son got into trouble at school for spitting. My wife and I took away his TV privileges for a week. We made him write apology letters to the school. And, of course, we decided that neither he nor I could ever make any type of spitting noise again, including the hot-rod sound we made when driving cars.

When my son and I walked out of the house the other day, we really only went to the garage to store his box of cars in the rafters. (The backpack was for dramatic effect.) The cars will remain in the garage . . . unless we can think of a new, fun way to drive them without spitting.

E-mail Michael Picarella at michael.picarella@gmail.com. To read more of his stories, go to www.michaelpicarellacolumn .blogspot.com.