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Piston slap ?

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Just a quick one if your car has piston slap would you use more engine oil my car has a knock in morning for a little bit till it get up to temp but I did have a noise like this a few weeks ago start off like this and turned out to be something loose in the engine my car only has 42k on and is a 2.0l blob wrx maybe it's just me and the bracket is starting to come loose again thanks for any advice

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Hi mate, mine slaps like it's going to jump out the engine bay. But mines a my97 with 130k on and the 97 cars have the worst reputation for doing it, the piston skirt design was changed after.

Car uses no oil at all and I've put full & semi synthetic in over the last couple of years,

At 42k I wouldn't expect yours to slap too much. What oil are you using & any mods done have you had the belts changed yet ?

Could be the belt tensioner if you look on YouTube there's vids showing it makes a knocking noise when worn

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I just got car 8 weeks ago come with a fresh service so not sure on what kind of oil was used probably just what grade subaru recommend I got the garage to put a timing belt kit on and new water pump car is stock I done about 1200 miles after I got car and had a noise that stared off like a knock then a rattle as the car reved put it back in and thay said something had come loose maybe it's just that starting again av now done 2200 miles since a got car and it's never used any oil just thought if your car had piston slap it might use more oil just so it can be ruled out

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Nah don't think they do it's only the pistons rattling around when cold, I'll post up a vid of mine should make you feel a bit better, does it go away when warm ?

Have a look for subaru rod knock on ytube to see what that sounds like !

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a 2003 blob wrx shouldn't have piston slap, they use Hypereutectic Pistons. they are stronger than cast pistons and have more silicone in, but not as strong as forged.

Hypereutectic Pistons don't expand and are machined to very tight tolerances. forged pistons expand when they get hot (hence the slap when cold) and once warm, are very strong


my blob wrx is running 330bhp and 109k on the clock, not even a sign of a rattle on start up.


I think they need to investigate further

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