Hi all, this is my first impreza so Im new to the faults of this model.
Mine has a noise on idle which I can only describe as piston slap as its not tappets, this noise gets quieter as the car warms up, and at higher revs than idle the noise goes. The engine has been re-built with competition forged pistons and a genuine subaru block 20,000 miles ago...could it be the forged pistons making it noisy? Its still audible when hot, so thats what concerned me mainly as I have read a few posts about it with conflicting info.

Thanks.

 

no one?

 

hi i have a sti ra with piston slap when cold and have read its down to forged pistons the noise goes when engine hot though

 

Just phoned the guy who built the engine, and he said its quite normal for this engine to make the noise - if it has forged pistons with hardly any skirts on them... Made me feel slightly more relieved that this piston slap is also on his own car that he has built for rallying, and he also said that his was running 1.7 bar boost.