FOUND THE PROBLEM I WAS HAVING WITH SURGING ENGINE AND LOW OIL PRESSURE. ALL INJECTORS HAD TO BE REPLACED. HAD TO TAKE IT OUT OF TOWN TO GET IT DONE. THE OIL PRESSURE DROPPING IS NORMAL FOR THE DURAMAXhttp://www.dieselplace.com/forum/smileys/Thumbs Up.gifSO DARN HAPPY NOW! E-HAAAAAW

What engine do you have LB7 or LLY, what year truck?

Oil pressure drops because the oil becomes diluted with diesel fuel.