I've got my M90 in hand and was taking it apart for a good cleaning. The PCV valve cover has some sort of gray RTV type of sealant on it. Is this stock? The PCV valve in there looks pretty old (donor car I believe is a ~80k mile 02/03 Bonnie) so it might be original.
Is this some sort of factory sealant? Did someone not know what they were doing when they changed it and added sealant? After opening it, I find it pretty much useless to seal again and scraped it all off.