2003 Malibu 3.1 V6 engine ticking/knocking

I have a 2003 Malibu with a 3.1 V6 it has about 85k miles. I was having to add a little coolant every 6 months or so for a while and I noticed a nasty oily substance in the resivior. I know DEX-Cool and all that. What happened was my oil pressure dropped to nothing. We towed the car to a friends garage. He’s a pretty good mechanic and after researching on the net we foud out about the DEX-Cool so after an intake manifold gasket, oil pump replacement, oil/filter change, and a radiator flush we start the car and there is a knock or tick. He took it back apart and pullrd the kifters and cleaned them put it all back together and the tick/knock is still there. All I have is a Haynes book for the car and most of the photos are for a 4 cylinder. Can anyone tell me where I can find an exploded drawing of the lifters or a picture? Does anyone have any Idea of what, other than the lifter, could be causing the noise? Thanks in advance.


I suppose it’s most important to know if it is a tick or a knock. Does it sound like it makes the noise every revolution of the crankshaft or every two revolutions? Does it sound like it’s coming from the top or bottom end of the engine? Usually when this situation occurs it is the engine bearings that suffer the most, not the lifters. How’s the oil pressure after the new parts? I hate to say it, but you may have damaged rod or main bearings.