What is Rotella T 15w 40 engine oil Zddp level? I have a 80 T/A turbo and would like to know what oilhas enough ZDDp in it for the flat tappet cam shaft.
That might be a possiblity due to a Syn oils better cleaning ability and you had some crude plugging up a bad area of a hard shrunken up seal. But today's oils have seal additives to help with possible seal issues.