Brothers Tom, left, and Ray Magliozzi pose under a car hood in 1991. (Susan Walsh/AP)

Tom Magliozzi, a car-repair expert who with his brother Ray brought a devilish sense of humor to public radio, entertaining millions of listeners with their “Car Talk” show that combined sibling-razzing wisecracks with savant-like mechanical diagnostics, died Nov. 3 in Belmont, Mass. He was 77.

NPR, which broadcasts the show nationally, announced his death and said the cause was complications from Alzheimer’s disease.

The Magliozzis, graduates of the Massachusetts Institute of Technology, were owners of the Good News Garage in Cambridge, Mass., when they debuted their talk-radio show in 1977 on WBUR in Boston.

NPR began syndicating the show a decade later, broadening public radio beyond its regular offerings of politics and current-affairs programming.

Explaining the program’s appeal, one broadcast executive told Rolling Stone, “Even our classical stations are picking the show up, though Vivaldi and ‘Car Talk’ don’t seem to go together. . . . It’s just a phenomenon.”

Brothers Tom, left, and Ray Magliozzi, hosts of National Public Radio's "Car Talk" show, pose on the back of a pick-up truck in Cambridge, Mass., on June 19, 2008. (Charles Krupa/Associated Press)

By 2005, the Magliozzis — who called themselves “Click and Clack, the Tappet Brothers,” or else “Fender Face” and “Piston Puss” — drew 4.7 million listeners a week on nearly 600 stations.

They also had a syndicated newspaper column, offering tips to those who viewed their cars as the offspring of Stephen King’s possessed vehicle Christine.

The arcana of engine and auto-body maintenance intimidates many drivers, but the Magliozzis captivated listeners by demystifying, debunking and plain disrespecting the work of the profession’s gatekeepers, from the blowhard garage mechanic to the boardroom executive of Detroit.

Tom Magliozzi once held up the Chevrolet minivan for ridicule, questioning why it needed 13 cup-holders.

“That’s one area where General Motors has excelled,” he said. “When people talk about the Japanese being ahead of us, they don’t hold a patch to us in cup holders.”

With their thick Boston accents and naughty-boy cackling, the Magliozzi brothers brought an earthy, blue-collar appeal that is not generally regarded as a hallmark of public radio. They teased their executive producer, crediting him as Doug “the subway fugitive, not a slave to fashion, bongo boy frogman” Berman. They signed off their program with the warning, “Don’t drive like my brother.”

The hosts seemed to relish opportunities to mimic the groans, bangs and murmurs of car trouble. Mostly, they offered listeners what a mysterious rattle likely meant and tips on how not to get cowed or ripped off by body-shop personnel.

“Most mechanics are men and men are all wrapped up in this machismo,” Tom Magliozzi once told Entertainment Weekly. “They can’t admit they’re wrong. Rather than admit they put the wrong part in, they try to cover by making things up.”

He opined about related professions: “Is there anything lower in the earth than a tow-truck driver?”

On the mediocrity of American cars: “You wanna buy a Festiva? Great. You’ll love it. Comes with a funeral wreath right on it.”

On how to know if you have a good mechanic: “By the size of his boat.”

The Magliozzis indulged in digressive, free-for-all conversations with listeners, who didn’t seem to mind playing the constant straight man or woman to two insatiable clowns in exchange for a soupcon of practical advice.

A caller named Bertha told the hosts that her new Toyota had “a lot of noise coming from the back.”

Tom: “You got any kids?”

Bertha: “No, not that small.”

Tom: “What about your neighbors? Are any of them missing kids?”

Ray: “You should replace the tires. And you may discover you miss the noise. Don’t throw those old tires away.”

The oldest of three siblings, Thomas Louis Magliozzi (pronounced “mah-lee-OTT-zee”) was born in East Cambridge, Mass., on June 28, 1937, and grew up in an Italian American neighborhood. His father ran a home-heating-oil business. Tom later teased his mother, a homemaker, by telling listeners she was “the only woman in the world who makes gravy with the Rolaids crushed right into it.”

As youngsters, Tom and Ray, who is 12 years his junior, conducted science experiments in the back yard and enjoyed tinkering with their father’s Depression-era car. Tom received a scholarship to attend MIT and graduated in 1958 with a degree in chemical engineering and economics.

“I turned down Harvard, because MIT gave me 200 bucks more for scholarship money, and that was big bucks back in 1880,” he quipped.

He received an MBA and spent a dozen years as a marketing and engineering expert for a company that manufactured automotive-control systems before he got bored and quit; he later earned a doctorate in marketing from Boston University. He joinedRay in the early 1970s in opening Hacker’s Haven, a do-it-yourself car-repair shop in Cambridge at which patrons could borrow tools and equipment. It evolved into the more professional Good News Garage.

In 1976, WBUR invited a group of local mechanics on the air to talk cars. Only Tom bothered to show up, figuring it was free publicity. The next week, he brought his brother. This engagement evolved into the weekly “Car Talk” segment on WBUR.

Their nickname — “Click and Clack” — was apparently rooted in a term used by car mechanics for the “tappet noise” of a misaligned valve.

The radio show took off, making him a national celebrity. Despite the success of “Car Talk” on the radio, efforts to harness their popularity in other media failed.

A short-lived CBS sitcom, “The George Wendt Show” (1995), seemed loosely based on their lives. The PBS animated series “Click and Clack’s As the Wrench Turns” (2008), featuring the Magliozzis doing voice-over, was quickly canceled.

“Car Talk,” however, drives on, in repeats after the Magliozzis stopped recording shows in 2012.

Mr. Magliozzi’s two marriages ended in divorce. Besides his brother, survivors include a companion, Sylvia Soderberg; a daughter from his first marriage; two children from his second marriage; a sister; and five grandchildren.

Mr. Magliozzi, who once campaigned with limited impact to stem the trend of gas-guzzling sport-utility vehicles, favored different cars over the years. At one point, he said he drove a 1963 Dodge Dart convertible. At another, it was a 1974 Chevy Caprice. “I had a Toyota once,” he said, “but it was too reliable.”