The findings are detailed in a report from the House Energy & Commerce Committee, which on Tuesday will hold hearings into the delayed recall of faulty ignition switches now linked to 13 deaths.
In 2007, an official with the National Highway Traffic Safety Administration pushed to open an investigation after noticing "a pattern of reported (airbag) non-deployments" involving Chevrolet Cobalts and Saturn Ions. But the official was blocked by others in the department who didn't believe action was warranted.
In addition, the report notes that GM rejected a proposed repair of faulty ignition switches because of cost.
General Motors ( had previously acknowledged that some engineers first noticed the issue as early as 2004, and that it had rejected the proposed fix in 2005. )
According to the House report, GM engineers decided against the proposed fix at least partly because the "tooling cost and piece price are too high" and because "none of the solutions represents an acceptable business case."
GM engineers also said that none of the fixes would fully correct the problem.
In the end, the Cobalt, Ion, along with the Chevy HHR, Pontiac G5 and Solstice and the Saturn Sky were not recalled by GM until February this year. That recall has grown to 2.6 million cars worldwide.
The problem is that the vehicles' ignition switches can be bumped into the "Off" or "Accessory" position while the vehicle is running, disabling the power steering, power braking and airbags.
The House report, which was released Sunday, details at least three deaths following GM's 2005 decision not to act, one of which was in 2009 after NHTSA's decision not to order a probe. GM has settled at least one case for a fatal crash that occurred in 2010.
The House report also says GM knew the ignition switch was substandard even earlier than 2004.
Officials at Delphi, which supplied the part, told investigators "that GM approved the (part) even though sample testing of the ignition switch torque was below the original specifications set by GM."
In addition to the proposed investigation in 2007, regulators considered a probe in 2010. Again, they "determined the data did not show a trend," according to the report.
NHTSA, in a statement Monday, said the information available to it in 2007 didn't warrant opening a formal probe.
"Recent data presented by GM provides new information and evidence directly linking the ignition switch to the airbag non-deployment," the agency said. "That's why we are aggressively investigating the timing of GM's recall."
General Motors also responded to the report on Monday, saying it "deeply regrets the events that led to the recall" and that it is fully cooperating with NHTSA and Congress. "Today's GM is committed to learning from the past while embracing the highest standards now and in the future," the automaker said.
The House committee cautioned that its timeline was "preliminary and incomplete" because it expects to receive additional documents. It said it has so far "received and reviewed over 200,000 pages of documents from GM and approximately 6,000 pages from NHTSA" and held meetings with officials from the government, General Motors and GM suppliers.
GM CEO Mary Barra and NHTSA acting administrator David Friedman will testify before the House panel on Tuesday and a Senate committee on Wednesday.
Although it first announced the recall in February, GM said parts to repair the vehicles will not be available until April. It has told customers their vehicles are safe to drive if they remove all objects except the vehicle's key from the keychain.