NHTSA investigates 500,000 Ford Motor sedans for potential steering problems

UPDATED: 7/11/14 1:56 pm ET - adds links

The National Highway Traffic Safety Administration will investigate an estimated 500,000 Ford Motor Co. sedans for potential steering problems, the agency said today.

The inquiry involves 2004-07 Ford Crown Victoria, Mercury Grand Marquis and Mercury Marauder units. NHTSA decided to open a preliminary evaluation of the vehicles on Monday after receiving five complaints, including one reported injury.

NHTSA said it will examine “incidents of steering shaft obstruction caused by interference from a dislodged heat shield.” In one case reported in April, a 2004 Crown Victoria in the Detroit area rolled over after the steering locked, causing neck and lower back injuries to the driver.

The driver said in the complaint that he found the heat shield under the car, and it was apparent the part had rusted off. The complaint attributed the separation to salt corrosion.

Additional complaints reported tight or difficult steering, sometimes requiring the use of “bodily force” to turn the wheel in the 2004 Crown Victoria and Grand Marquis.

NHTSA typically opens a preliminary evaluation when consumer complaints or manufacturer service bulletins suggest there may be a harmful defect. Once that evaluation is complete, the agency begins an engineering analysis or closes the inquiry. Based on the outcome of the engineering analysis, a vehicle may be recalled or the investigation may be closed without further action.

Ford issued a recall in August 2013 for 335,000 2005-11 Crown Victoria, Grand Marquis and Lincoln Town Cars -- typically police vehicles -- in states with heavy salt use for corrosion that could seize the lower intermediate shaft, which could cause the upper intermediate steering shaft to collapse. The vehicles were recalled after a NHTSA investigation sparked by 22 incidents related to steering separation.

The company said it plans to cooperate in the current investigation.

You can reach Kathleen Burke at kgburke@umich.edu