comprission is all good but number 4 is 2 bar lowere then the rest all the others are at 8 bar and number 4 is betwwen 6/ 7 bar so it s not that much off a differance pisston rings were changed about 900 miles ago and it had new steam seals 900 miles a go to so i donot no weather to strip it all down and do it all from scratch then i now its done proper but a ring could be fucked or steam seal could of lefted or split dont mind doing the work just liked to now befor i do any work