A tight engine may be to blame for a recent Fisker Karma fire.

A garage fire involving a Fisker Karma last week in Texas may have been the result of poor engine packaging, a new report finds. Initial reports suggested the hybrid's lithium-ion battery pack could be at fault.

Jon Bereisa, CEO of consultancy Auto Lectrification and a former General Motors engineer that worked on both the EV1 and the Chevrolet Volt, revealed to Automotive News that the cause of the Karma fire was likely due to the sedan's tight engine and exhaust packaging, not the hybrid's battery pack.

"That engine is shoehorned into that bay, because they had to use a larger engine, because it was too heavy a car," Bereisa said. "As a result, there's no room for exhaust routing and heat shielding to route the heat away."

Any kind of fluid leak combined with those cramped conditions would be enough to spark a fire, Bereisa said.

Bereisa says his theory is supported by the eyewitness account of Jeremy Gutierrez, the owner of the Karma in question. Gutierrez said he smelled burning rubber just before the fire, which Bereisa says indicates the blaze started under the Karma's hood.

"You don't smell rubber with batteries, but you will if it's something on the engine."

Authorities haven't identified what sent the Karma up in flames, but the car's battery pack was found intact, indicating it wasn't the source of the fire.