It may be all smiles and friendly skies out in Norman Mineta San Jose International Airport's newly renovated Terminal A lobby, but in the airline offices behind the ticket counter, it really stinks.

A mysterious noxious smell has been plaguing the terminal intermittently for at least the past five months.

"It's like being in an outhouse," said Steve Newell, general manager of the US Airways San Jose field station.

City officials have propped open the back doors and brought in big fans and industrial odor-neutralizing machines. They put picnic tables outside for airline staffers to escape the stench at lunch and have repeatedly pumped smoke through the plumbing after hours. They have run video cameras through the lines to detect leaks and fixed several already.

But the sewerlike smell, which is apparently confined to office areas of the terminal, keeps coming back. And some airline officials are so fed up that they're threatening to withhold hundreds of thousands of dollars in monthly rent payments to the city until it goes away.

"We're at the end of our straw," Newell said Wednesday. "The last two days, it came back like gangbusters. It was literally like you stuck your head in a septic tank. Short-term, you can put up with it. But eight to 10 hours a day, it's horrible."

City officials say they're frustrated, too.

"It's something we've taken extremely seriously," said the city's airport spokesman, David Vossbrink. "Obviously, all of us want to fix it. Although we've made improvements, we haven't been 100 percent successful yet. It continues to elude a solution."

Vossbrink said there have been no complaints from passengers, only airline officials and employees. No airlines, he added, have withheld rent. The sewer smell was not evident in the airline offices by midday Wednesday, only a fruity air-freshener odor.

But whirring fans, humming ozone generators and a paper sign taped to the wall listing a city official to call about the "sewer smell" attested to the problem.

Terminal A originally opened in 1990 and housed Southwest and American airlines as principal tenants. It recently got a $186 million remodel as part of the airport's $1.3 billion renovation, which included a newly built Terminal B. Southwest, Alaska and Delta have now moved to Terminal B, while JetBlue, United, Continental and US Airways left the old Terminal C for Terminal A.

In many ways, Newell said, the remodeled terminal is an improvement.

"As far as outside the facilities and what they did upstairs, it's fantastic," Newell said.

But the odor problem, airline officials say, has become intolerable.

"It's got to be resolved somehow," said Urban Grass, general manager for Continental in San Jose. He said the smell has stunk up his accounting area and employee break room, and that the United and US Airways offices down the hall are "horrible."

The sewer smell isn't the only problem to emerge with the airport overhaul. The waterless urinals in the men's rooms "were not as effective as hoped," Vossbrink said, and are being replaced with standard flush models.

But airline staffers' top concern has been the office stench.

Airline officials suspect shoddy subcontractor work tapping into the plumbing lines is somehow to blame.

Officials at Hensel Phelps Construction, the general contractor for the airport makeover, deferred comment to the airport.

Newell said that Wednesday morning, city officials brought out picnic tables for staffers to eat outside and removed a bucket they had hung from an overhead sewer line that had been dripping repeatedly onto a baggage conveyor belt. Airline officials made their frustration clear to airport management at a meeting Tuesday, he said.

Airport officials plan to smoke out the plumbing a fourth time to hunt for more leaks next week.

"We're working as hard as we can to identify it and eliminate it," Vossbrink said. "We expect it to be found in either the plumbing not being done 100 percent right or something undone during construction. But the hard part is that it's also intermittent and random."

Airline officials said that they do appreciate the airport's efforts but still grumble about a seeming lack of accountability for the problem.

"There's a lot of this going on," Newell said as he made a finger-pointing motion.

"At some point or another," Grass added, "they've got to come up with a solution and make this wrong a right."

Contact John Woolfolk at 408-975-9346.