have got bad tapping from cold at 2500rpm on my 93 wrx.havnt noticed it before but changed oil/filter with magnatec last week(pre filled filter and disconnected crank sensor).goes after a bit when warmed up. after doing search concensus is piston slap.car has cdb and have been told some early ones with cdb have forged parts same as v1 sti.
not really impressed with the oil and going to change again this weekend.
any other things to check???

 

get an oil pressue reading might be oil pump a bit worn because if it was a bearing or piston slap it would not go away. Good luck.

 

my 93 wrx knocks when cold. forget about it.

 

Piston slap should go away as the engine reaches working temperature. If it doesn't you can assume there's either excessive clearance or physical damage to piston or rings.
Piston slap is usually most noticable 30-60 secs after starting from cold and gently 'blipping' the throttle. On some engines there may be the slightest hint of slap with the engine at working temp. and at low engine speeds - it tends to smooth out as the revs rise.
Slap has been around since the birth of the internal combustion engine!

JohnD

 

seems like slap then, as when car warmed up a bit it quietens down loads.havnt decided what to do with engine at the moment as its a cdb and would be ideal for big power build if the mrs lets me.

 

well just got in and as i was letting car tick over stuck my head under front to hear something rattling around sump....
bollocks!car not knocking or anything so dropping oil in morning and see what drops out.if dead how much closed deck block worth???