I have just replaced the 350 engine in my 97 suburban (the old one had
150,000 miles with very low compression in two cylinders). I have replaced it with a new GM long block. What is bothering me is a "knocking" sound that I get when it is first started up cold. It is a knocking sound that sounds the loudest around the oil pan. From what I have always been told.. a rod knock gets worse when the engine warms up, a piston slap goes away as the engine warms up. I have the knock for about two minutes and then it seems to be gone. The engine now has 1000 miles on it and the noise has not changed at all. Do I have a serious problem? What is the probable cause?Thanks MJ