Main Vauxhall dealer did an oil change on my 57 plate Vectra, but used incorrect oil (10w 40), instead of fully synthetic 5w 30. They have now changed it to correct oil, but suggested the only way to check for any damage or engine wear is to take engine apart and rebuild. Can anyone give any advice on whether this is worthwhile and if done will it get put back together in same way as when new, or should i just leave it as is?