Mobil Pays for Damage Caused by Faulty Fuel : Gasoline: A double dose of rust inhibitor is in product sold in Orange, Los Angeles counties. Cars conk out, and firm pays off.

Douglas Johnston knew he had a problem when he tried to accelerate in his 1976 Mercedes-Benz convertible about a month ago.

“It’s like half the cylinders weren’t working,” Johnston said. “The Fourth of July weekend was shot, because I was afraid to take it anywhere.”

At about the same time, Greg Wilson found that his high-performance 1989 Ford Taurus was losing power during his daily commute from his home in Huntington Beach to his job in Manhattan Beach.

“It would act like you were starting to run out of gas,” Wilson said.

Johnston, Wilson and hundreds of other drivers had received Mobil gasoline with a hidden problem: a double dose of rust inhibitor.

The problem was later traced to a loading terminal at Mobil’s Torrance refinery. Rust inhibitor was mistakenly added to the gasoline instead of detergent, Mobil spokesmen said.

The faulty fuel was sold at 98 Mobil stations in Orange and Los Angeles counties.

Fuel systems rebelled. Cars that had tanked up with the contaminated gas began shuddering, sputtering, stalling.

Mobil Oil Corp. announced June 28 that it had accidentally distributed tainted gas and promised to reimburse motorists for damage.

Now the oil giant is paying to clean the fuel systems. James Amanna, a spokesman at Mobil’s headquarters in Fairfax, Va., refused Thursday to make public the number of cars repaired or the total bill footed by Mobil.

That information is “immaterial,” said Amanna, who did confirm that hundreds of cars were affected, primarily in the South Bay part of Los Angeles County.

“The story is, from our standpoint, that we responded to each complaint,” Amanna said.

Random inquiries at 12 dealerships and repair shops this week found more than 300 cars that were serviced for the Mobil gas problem, with bills ranging from $150 to $500 or more per car. Work ranged from simply cleaning the fuel lines to replacing damaged fuel pumps.

Some service managers praised Mobil’s response this week. “Mobil was very gracious through this whole deal,” said Bill Messenger, service manager at Torrance Nissan Inc., which repaired 34 cars with the gasoline problem. “They were very, very easy to deal with.”

“Everything we suggested to have done, they agreed with,” said Thomas McElhone, owner and manager of South Bay Imported Cars in Redondo Beach.

Some repair shops were flooded with customers complaining about cars hesitating and stalling. Joe Dalven, service manager at South Bay Toyota Inc. in Gardena, said: “The first part of the month, it seemed like we were busy all the time, every day. . . . We were doing seven or eight a day.”

His firm, which repaired more than 100 cars, arranged to do the work and then be reimbursed by Mobil’s insurance company.

Wilson, whose Taurus had problems, is parts and service chief at Manhattan Ford in Manhattan Beach, which worked on 35 to 40 cars.

Wilson’s Taurus cost more than $300 to repair. But some bills were higher. One repair bill at Manhattan Ford totaled $1,362, for a car with a damaged fuel pump and fuel injectors.

Most cars needed less work: a drained gas tank, flushed lines and new filters.

Wilson said he is pleased with how repairs were handled. “Sure, no one likes the inconvenience,” he said, but “I feel real good, because Mobil was real fair about it.”

Johnston paid $170 to have his Mercedes-Benz repaired. He is awaiting a check from Mobil’s insurance firm.

As for his car: “It’s acted fine since.”