The Montgomery County Police Department has called in one-third of its fleet of marked police cruisers for immediate inspection, the department said Tuesday.

The department said 324 Ford Crown Victoria Police Interceptors, including 303 in the marked cruiser fleet, were to be inspected after a potential steering problem was identified in model years 2005 to 2011.

Normal police operations are not being affected during the inspections, the department said. It said officers who are assigned to drive the Crown Victorias have doubled with officers whose vehicles were not called in.

Police said that many of the cars have gone back into service “without issues” and that the entire Crown Victoria fleet “should be back in service by Saturday.”

It was not immediately clear Tuesday night how many of the Crown Victorias would have been on the streets under normal patrol schedules or how many officers have doubled up. The budget approved for fiscal 2012 called for 1,602 full-time and 198 part-time police positions. Police said the 303 marked Crown Victorias made up about 33 percent of the marked vehicle fleet.

Police said that since July, two cruisers had been affected by a defect that could cause a steering failure during normal operation. One incident was in July and the other last week.

No injury or collision resulted from either incident, police said. They said the defect was identified by the county after the second incident.

After learning of the defect, police said, Chief J. Thomas Manger ordered that the 324 Crown Victorias be brought in for immediate inspection. They were barred from patrol until cleared of any possible defect, police said.

In a statement issued Tuesday night, the department said that the Fleet Management Division of the county’s General Services Department put an aggressive inspection process into effect Tuesday and that of 172 vehicles already inspected, 127 have been returned to service without issues.

Police said Crown Victorias that were not assigned to an officer were the first to be inspected and cleared. Those were made available to officers whose vehicles were undergoing inspection.

The county said it has checked with other jurisdictions and has learned of no other incidents involving the steering problem.