hi i would appreciate any opinions i was snow plowing went noticed oil leak at first thought it was coming from oil pressure switch truck was full of snow changed switch started to plow again checked truck and was still leaking oil put in shop let it thaw out started truck no oil leak after 20 minutes or so oil leak started seems like tappet cover plan to change this weekend is there any thing i should check that might cause tappet cover to fail truck has 366000 kms on it it was cold and not plugged in thanks in advance for any help