Hello All,

I just got a 99 VX . The previous owner was supposedly using Mobile1 10W40. When I got the car I switched to Mobile 1 5W30. Anyways I was hearing a slight knock from the engine when I got it. So I decided to put Seafoam in the crack and intake. After putting the seafoam the knock sounds slightly louder. I do not hear a knock on idle but do from 2.5K to 3.5K rpm or so. I also believe the knock gets louder on load (driving it in 1st gear for example). I cleaned the EGR valve when I changed my oil not sure if it is leaking. I have a new PCV. I do not think the timing belt have been changed nor the valves been adjusted. I own a 1989 BMW 325ix that needs the valves adjust but it does not sound so loud. I really like the car but I am worried I might have a problem with my rod bearings. Does the rod bearing knock only happen at certain RPMs?

I did an extensive search and read many many posts regarding the engine knock but it seems like everyone had a knock on idle not at certain rpms only.

Your input and help is very much appreciated!