hi guys, how noisy is a impreza engine once fitted with forged pistons?
mine is really noisy, almost sounds like its knocking as if the bearings have gone!! its only noisy on idle!!! once you rev it a bit it's ok??
is this normal???

 

what build have you got?
2L, 2.5 etc

 

Might be the timing belt tensioner knocking on idle.

Mick

 

ive got the same thing only on idle till up to temp. dont worry

 

it's a 2.0, well 2038.
even when hot its still noisy, also fitted a new tensioner.
is it just piston slap??

 

dont worry i have forged pistons once warm they are fine

 

my 2.1 stroker is like that, idle there is a small tapping like sound, cold or hot, but as soon as the reves pick up it goes away.

have heard another 2.1 stroker and it was the same. went back to the garage and they also said it was all fine.

i think forged builds just sometime sound different depending on make of parts, size/gap on pistons etc etc

 

thanks for the reasurance guys
on my 2nd rebuild in a year, can't afford another one,
many thanks!!!!

 

noise when cold is normal for a forged engine. i would not be so happy if the noise was still there when the engine is hot, hence you need to keep an eye on the oil consumption. mine slaps when cold but it doesnt use oil so im happy to live with it. my engine isnt forged either!

 

it's noisy pretty much all the time, even when up to temp, only at idle though? just fitted new crankshaft, new con rods and new bearings, so it can't be the bearings....i hope

 

What injectors do you have?
I fitted Denso 650's and the noise on tick over(cold or warm) is dam loud.

 

standard 550's, but recently got them checked and cleaned.