Low Oil Pressure Light on Cold Start

[Homeoboxter]

Different filters may have different resistance for the oil flow, depending on the pore size. Normally this should not make any difference to a properly functioning engine. Probably you have a leak somewhere in the system. This can be a lot of things, like a broken o-ring at the pick up tube, damaged oil pump rotors or something at the relief valve, etc. I would think the oil pump can`t keep up with the increased resistance given by the better filter. With the engine warming up it gets easier for the pump to push the oil through the filter material, hence the oil lamp flickering stops. I would drop the sump and start inspecting things around there.

[ecp]

Originally Posted by Homeoboxter

Different filters may have different resistance for the oil flow, depending on the pore size. Normally this should not make any difference to a properly functioning engine. Probably you have a leak somewhere in the system. This can be a lot of things, like a broken o-ring at the pick up tube, damaged oil pump rotors or something at the relief valve, etc. I would think the oil pump can`t keep up with the increased resistance given by the better filter. With the engine warming up it gets easier for the pump to push the oil through the filter material, hence the oil lamp flickering stops. I would drop the sump and start inspecting things around there.

I looked, seems like I have some oil coming from where the pump slides into the block, where the hex drive is. I have a feeling there’s a problem that’s just being highlighted by the more resistance from the oil filter. The sump has definitely been dropped before. Going to change the filter and try cranking it with the ignition relay pulled and then see what happens when it fires up. If it’s fine after the cranking then I’m going to lean towards a worn pump not building pressure fast enough

[ecp]

Just an update, saturday I took the car out. When I got to the light in my neighborhood it started running rough. I shut it off and started it back up, ran fine. Went to the gas station and filled up and it was fine. Was decelerating down a slight hill and the oil light came on. Shut it off and coasted and pulled over. Started it up and it was fine all the way home. I have it up on ramps at my house. Started it up the next day, same clanking and oil light. Shut it off. Then later in the day, I pulled the ignition fuse and cranked it quite a bit. Put the fuse back in and it started up flawlessly. No odd noises and it seemed to run really really smooth.

As of right now my plan is to replace the oil pump and also drop the oil pan and reseal/ inspect pickup tube and everything else. The oil pump looks like no joke of a job so I’m not looking forward to it, but it is leaking and needs to be addressed anyway.
Does this sound like the right path to go down? I’m not driving the car except in the garage once I have room. Too scared of that light coming back on. It’s really confusing how sometimes the engine actually runs rough, but was flawless after just cranking it extra with the fuse pulled.

[blue62]

First thing is do what JFP said in his post #8.
second do what it takes to fix the oil leak at the oil pump.
Then re-evaluate the situation.

[ecp]

Originally Posted by blue62

First thing is do what JFP said in his post #8.
second do what it takes to fix the oil leak at the oil pump.
Then re-evaluate the situation.

I’m gonna get a new filter and get a gauge. Any suggestions for pressure gauges? Or could I rent one from the auto parts store that would work? Also where is the oil pressure sender so I know where to hook it up?