Please bear with me here as hope this makes sense.....took my head of today due to knowing by research I need to change the valve stem seals (bearing in mind before I go on my starlet had a full engine rebuild with receipts which I have less then a year ago) a week a go a compression test was done all about the same in the last 150's so that's fine, anyway back to, today, head off then we looked at the pistons just to see while the head is off, when we rotated the crank pulley so 2 pistons were at the top there was alittle play in both pistons 2 and 3 and also same with 1 and 4 when they were at the top too when I say play they moved up and down a mm or 2, (never had piston slap before it knocking when the car was running) also my mechanic done some leak test what ever he put in each bore just to see if it would go down, and in time it did very very slowly though, whatever it was it was very thin, not as thick as oil, which of course has gone into the sump, to me is it the rings? Everything else seems fine, I can only think seing as it's been rebuild in less then a year ago it has the wrong size rings on? It's kind of got me thinking alot here, as what I have just said May be normal on starlets just need to know before everything else goes back on, sorry for the long story hope it all makes sense. Thanks Pat