i have a 2wd cosworth the piston slap has been there since i bought the car but went away when warm now after av changed the oil to 10/60 fully syn oil the noise seems to be stayin alot longer and slight noise even when warmed up. the oil a was using was 10/40 fully syn only reason a used it was a had it sitting for my old car a sold

 

my car used to have noisy tappets on 10/60 and stupidly high oil pressure as well lol
since i changed to 10/50 its a lot quieter

 

Always use 10/40 in mine.

Steve

 

pain in the arse think al change the oil again waste of good oil tho but worth it if the noise go,s

 

fully or semi mate?

 

its always ran fully

 

I had piston slap even when warm, oil didn't help, yours may just be getting a bit long in the tooth, how many miles has the bottom end done ?, mine had 200K so was entitled to be noisy!!
tabetha

 

77000miles. rebuilt 15000m ago roughly. if a,d a done 200k ad be noisy

 

15,000 rebuild should be dead quiet, you sure it's slap you can hear, and not a lazy tappet that quietens down as the oil heats up ?
tabetha

 

its a diff sound to a tappet a had them done on my old cossie

 

Did you swap oil brands at the same time, some oils do seem to make the engine noisier than others ?
tabetha

 

yeh a did a had millers 10w60 sittn when a had ma evo n thot al use that tae use it up