Looking for technical advice on this issue I have. Here is the patient. 1997 evo with 80,000 miles on bottom end. Top end has approx 500miles (cam,lifters,pushrods and cam bearing approx 1500 miles). Noticed on my way home from work at intersection my oil pressure light comes on and gauge reads 0 psi. Engine is making no unusual noise even when motor rpm’s are increased. Light changes and I continue on listening for anything from the lifters hoping this is just a bad sending unit. 3-4 miles down the road the lifters start rattling and I immediately shut her down and coast to side of road. Oil level is good. Start her up again and still show no pressure but engine is quiet….Tow her home and following day I put new oil filter on and install mechanical gauge and start her up. Mechanical gauge shows approx 5psi cold at idle. I slowly apply rpm’s and pressure max’s out at 9-10psi… (Normaly factory gauge reads 20-30lbs cold at idle and 30-40 at speed) I pull off the cam cover and find nothing unusual. If I understand the service manual correctly the oil flows to the mechanical gauge first and lifters second. So I am thinking (scary I know) that it has to be the pump that is faulty or that the feed line to the pump has a blockage…Is this correct? I tried to get the oil pump off but the bolts are too long and hit the transmission case. So Am I on the right path here or am I missing something?

Thanks for ANYTHING that might help

 

Blockage or a bad pump... only thing I can think of.

 

First check the tappet screen..if it is blocked the gauge and the lifters will not get oil.

Second...if the pressure regulating valve is stuck or blocked open by trash, the pump will not make any pressure.