Volvo issues warning about unintended acceleration for eight models

The models affected are those that have the five-cylinder diesel engine, and include the S40 and V50 made from 2006-2010, the S80 made from 2007-2009, the C30 and C70 made from 2007-2010, the V70 and XC70 from 2008-2009 and the 2009 model year XC60.

Volvo has not issued a recall for these vehicles, but has sent out warning letters to 158,000 owners of these cars across Western Europe. Volvo Cars spokesman Per-Ake Froberg said that the issue is engine oil leaking into the combustion chamber. This works in the same way as fuel and causes an acceleration burst. "This has caused the engine to maintain or even increase its speed, even though the driver has removed his foot from the gas pedal," he said.

Froberg added that biodiesel mixed with conventional diesel is the primary cause, as it does not evaporate in the same manner as normal diesel fuel. This leads to extra fuel injected through the particle filter, which does not combust, and instead winds up combined with the engine oil. The oil level subsequently rises, and overflows into the combustion chamber.

Volvo claims that so far, 55 cases of unintended acceleration have been reported, and that no accidents have resulted from the incidents. "We have not had any accidents reported as a result of this, though. In the instances when this has occurred, the drivers have put the gear in neutral and stopped on the side of the road," Froberg said. Volvo has not yet come up with a solution to the problem.