(February 12, 2011) SANTA MONICA, Calif. — An increasing number of Chrysler, Dodge and Jeep owners are reporting fuel spit-back issues at the gas pump, according to an Edmunds.com analysis of complaints filed with the National Highway Traffic Safety Administration (NHTSA).

The complaints assert that the fuel system does not respond to a shut-off mechanism in affected vehicles, causing gas overflows that result in a spill or a spray.

The defect is not unknown to Chrysler. The Detroit automaker has recalled 45,000 2005 Dodge Durangos to correct the issue. But even as Chrysler has attempted to address the problem in that vehicle, other vehicles are exhibiting the same problem. Edmunds.com found that in January alone, 211 complaints were filed about the problem from Chrysler, Dodge, and Jeep owners.

The Jeep Wrangler appears to be most affected. Almost 900 owners of 2005-10 model year Wranglers filed fuel spit-back complaints with NHTSA between January 2009 and January 2011. The majority of those reports concerned the 2007 and 2008 model years. One complaint filed by a 2005 Jeep Wrangler owner last month says that the overfilling problem occurs "every single time I fill up at the gas station."

"There has been a continuous and increasing number of complaints submitted month-to-month on this topic, and we believe this should be brought to consumers' attention," said Panee Segal, an analyst at Edmunds.com.

Federal investigators might be receiving more reports about the issue because some Jeep Wrangler owners are using social media to encourage reporting of the problem. Wrangler spit-back has been discussed in the Edmunds.com community within the 2008 Jeep Wrangler discussion board. There is also a Facebook page dedicated to the issue and a post at JeepForum.com encouraging vehicle owners to submit complaints to federal investigators.

Edmunds.com reports that Chrysler responded in October 2010 to a NHTSA request for information about the problem. Chrysler said that the only "plausible" explanation for the spit-backs was an exposure to gasoline with high levels of ethanol that make the inlet check valve (ICV) susceptible to swelling, causing it to stick and fail to close properly.

Because "not a single allegation of crash, fire, property damage or injury" resulted from the problem, Chrysler claimed that there was no safety defect, and asked NHTSA to close the investigation. NHTSA, however, told Edmunds.com that its investigation into the issue "is still active."

Read the full story on Chrysler's fuel spit-back problem by Edmunds.com's features editor Carroll Lachnit.    

More analysis of this issue and other NHTSA complaint reports can be found in the Data Center on Edmunds' AutoObserver.com .