Mazda Motor Corporation has issued a recall notice for the Mazda 6 sedan for the second time in three years.
It seems that a species of spider named “Yellow Sac” enjoys the smell of gasoline in Mazda cars and weaves its web in a very inconvenient place, blocking a vent to the engine.
Reuters reports that Mazda informed U.S. regulators that it is proposing to recall 42,000 sedans fitted with the 2.5-liter engines. This recall applies to vehicles sold in the U.S. covering model years 2010 to 2012. Mazda officials could not confirm numbers for recalls outside of the United States.
In a classic example of history repeating itself, the previous recall was also for the same model. On that occasion, 65,000 vehicles from model years 2009 and 2010 had to be inspected for spider’s webs blocking evaporative canister vent lines.
Mazda informed the National Highway Traffic Safety Administration that this recall was for a similar reason to the first one.
The problem that the web causes is that it restricts the flow of fuel, which can then lead to reduced pressure in the fuel tank when the emission control system purges vapors from the evaporative canister.
This in turn puts stress on the fuel tank, which may crack and leak fuel, increasing the possibility of a fire.
But Mazda insists that it is not aware of any fires actually breaking out because of this risk.
In the 2011 recall, Mazda tried to fix the problem by adding a spring to the canister vent line to prevent spiders from crawling inside.
In general, that solution worked. But the spring itself was alleged to have caused a different problem, which led to several reports of cracked fuel tanks in sedans equipped with the spring.
After studying the nine cases in which tanks containing the spring were damaged, engineers determined that a change in the car’s software would keep tanks from cracking, even if a spider web were to block a vent.
Mazda will tell owners during the recall campaign to return cars to dealers, where the evaporative canister vent line will be checked and cleared if necessary. Also, the dealers will reprogram the software.
It should be clarified that this blockage problem does not occur in other models made by Mazda, and relates only in cars made at a plant in Flat Rock, Michigan, where Mazda once produced cars jointly with Ford Motor Co.
Mazda stopped production of cars at Flat Rock in August 2012.