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Car Sounds
Transmissions and Drivetrains
Chevy Impala
1995-2005 Chevy Cavaliers

What could cause a subtle knocking noise in the engine when it's cold and only when accelerating and gets quicker the faster you accelerate?

Answer

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Wiki User
January 20, 2008 11:23PM

I would say you either have a rod knocking or lifter knocking. I know in the 3.8 litre motors they are known to knock alittle when you cold start them. Most Grand Ams, Grand Prixs are like this. My sister has a 2002 Grand Am that does this and the noise goes away once it's warmed up. I would also double check and make sure your oil is full. get your car to a garage for a def solution.