I'm Neal and I am here to assist you. Only accept when you are happy with my assistance. If I can't help I will open your Question to other experts.
Most likely it is going to be the cam and lifters, they are known to fail in those.
these lifters are rollers on the cam not hydraulic wouldnt i be able to spot one visually
Not really. Sometimes you don't find the problem until it is apart.
But I am going from your description that it is coming from the valve train.
sorry to drop ya but had to do something "more important"?
my question was had you heard of this before going from absolute running fine to sounding like a diesel no miss no codes just racket that sounds like an isuzu customer walked in from behind and wondered if we worked on diesels too! i have not found anyone who has come across this prob with this motor so i will start from scratch and see what comesof it thanks for the help anyway