Risk of an engine fire from leaking motor oil this week prompted General Motors to recall a total of nearly 1.5 million model year 1997 to 2003 Buicks, Chevrolets, Oldsmobiles and Pontiacs.

Drops of engine oil may be deposited on the exhaust manifold through hard braking, GM advised the National Highway Traffic Safety Administration on April 8. If the manifold is hot enough and the oil runs below the heat shield, it could ignite into a small flame and spread to the plastic spark plug wire channel and beyond, increasing the risk of an engine compartment fire.

The recall, expected to begin during May 2009, applies to a total of 1,497,516 Buick Regals, Chevrolet Impalas, Luminas and Monte Carlos, Oldsmobile Intrigues and Pontiac Grand Prix. All the affected vehicles are midsize cars with a 3.8 liter V6 engine.

Dealers will remove the spark plug wire retention channel at the front of the engine and install two new spark plug wire retainers free of charge, GM said.