The National Highway Traffic Safety Administration (NHTSA) has closed the investigation of rapid coolant loss in 24,635 Porsche 911 cars manufactured between 2001 and 2011.  Models affected include the 911, GT2, GT3 and Turbo, along with other trims (GT2 RS, GT3 RS and Turbo S).

There was, according to Porsche a 'manufacturing quality issue with the supplier's application of adhesive to coolant pipe fittings that resulted in elevated failure rates.'

After investigating 63 complaints regarding the sudden coolant loss, it was determined that coolant loss happened when the vehicle was parked and there were no fittings separation that occurred that could compromise the safety of the vehicle while in motion.

No crashes, accidents or injuries have been attributed to the coolant leak prompting the NHTSA to close the investigation.

Despite this development, the NHTSA has not come out and said that his is not a safety-related issue.  The agency will continue to monitor the situation and take the appropriate action when necessary.