"checked oil seal it was installed correctly and not from Taiwan but no way to really check if it is sealing."
Best checked with oil pressure guage mounted into plug at front of timing cover.
Also, a dead give away is the little "o" ring spring sitting inside the timing cover oil seal cavity.
We have found the seals made by Pioneer Weston (mind you nearly all seals are made today in places far-away) to hold the most pressure when the oil is hot. The Pioneer seals are clearly marked POS 2072.
This is not to say that some engineer gets a better idea, or some bean counter figures he can make a penny more per seal by changing the rubber composition and we start to get failures with Pioneer seals. My favorite source of unexpected problems is when an "expert" gets a hold of one of these manufacturers and convinces them that what they have been doing right for all these years is wrong. Then the fun begins...
This has been something I watch closely. My first experience with Taiwan oil seals failing in this application was nearly forty years ago. I bought 5,000 from Taiwan and it wasn't long before the calls from dealers came in. We discovered that once the seals came up to engine temperature they would invert. Things are a little bit better with oriental oil feed seals today, but not much. We still find brands that will not hold the pressure when hot.
With all of the talk about increased volume oil pumps, it is all for naught if the pressure inverts this seal. You are going to have a very expensive engine failure with an expensive oil pump. We have built a small pressure device that allows us to check the performance of these seals and find the Pioneer Weston continues to out perform other brands when hot.