Oil Pressure Issue

[sergechronos]

How long have you owned it? Possibility that the oil didn't even make it to the pan when you added it (from say a blockage in the heads?) Did you actually get 5qts back out of it when you drained it, or was it substantially less?

Valve covers or oil pan ever been off? Possible that maybe you left something in the head when you did the lifters and it's partially obstructing an oil return port? Or maybe the oil pick up area on the pan is dented, or the pick up has come loose from the oil pump and isn't able to lift enough oil?

[Hyperfocus]

Oil is making it to the pan and the pan isn't dented. Undercarriage is flawless with zero leaks whatsoever. The car was very well kept which is why this is such a surprising issue.

Today I finally got around to the testing. No oil flow to the filter housing when turning the engine by hand or briefly with the starter. There's some unflattering noise from the oil pump area when trying to turn over the engine, but no metal particles in the old or new oil so my hopes are still high for the engine health. But there's no doubt I need to pull the pan and oil pump to find out just WTF is going on.

I've just never had an oil pump fail like this so I was hoping maybe there was some small, common issue that I'm not aware of such as a stuck relief valve or something. Obviously I haven't gotten that lucky...

[J. Fast]

don't use the starter anymore K.

open up the oil pump and pull the oil pump gears and reseal the pump housing empty. rent a lift pump and set it up to pull oil from the oil filter feed side from the oil pump to the filter housing. install an inline filter on the suction and feed side of the pump and start pulling vac till you've pressurized the system and are steadily lifting oil from the sump (oil pan). when you start lifting a solid column add about 5 quarts of oil and pull it thru and check the inline filters. if they're clean just change the oil pump and move along. if they're dirty... let's not talk about that scenario because you're pulling the engine bro.

good luck.

[anyonebutme]

if the pump intake pipe cracks or falls off (seen it), boom, no oil pressure at all. if the oil pressure relief jambs open (seen it), boom, little to no pressure at idle. if your center main bearings get smashed you'll also get no oil pressure at idle, have a car out back that suffers from that specific ailment right now. Oil pump gears breaking tend to take the front main seal out at the same time and dump oil all over, but I guess it's possible for the outer gear to come apart and not blow the seal, just never seen it on a 6G.

i personally would just go ahead and pull the pan, it's not a difficult job and will answer a lot of questions immediately. after that it's not a difficult job to remove the oil pump.

[anyonebutme]

don't use the starter anymore K.

open up the oil pump and pull the oil pump gears and reseal the pump housing empty. rent a lift pump and set it up to pull oil from the oil filter feed side from the oil pump to the filter housing. install an inline filter on the suction and feed side of the pump and start pulling vac till you've pressurized the system and are steadily lifting oil from the sump (oil pan). when you start lifting a solid column add about 5 quarts of oil and pull it thru and check the inline filters. if they're clean just change the oil pump and move along. if they're dirty... let's not talk about that scenario because you're pulling the engine bro.

good luck.

By the time he removes the pump to do all that, he would be staring right at the bearings anyways so why bother doing all that nonsense and instead just look at the bearings themselves?

[Boomer3000]

Take abms advice on this, believe me.

Just pull the pan and go from there. If you got lucky no bearings are smashed or even messed up. And you can just replace the pump no probs. if not then welcome to sbc.

[Hyperfocus]

if the pump intake pipe cracks or falls off (seen it), boom, no oil pressure at all. if the oil pressure relief jambs open (seen it), boom, little to no pressure at idle. if your center main bearings get smashed you'll also get no oil pressure at idle, have a car out back that suffers from that specific ailment right now. Oil pump gears breaking tend to take the front main seal out at the same time and dump oil all over, but I guess it's possible for the outer gear to come apart and not blow the seal, just never seen it on a 6G.

i personally would just go ahead and pull the pan, it's not a difficult job and will answer a lot of questions immediately. after that it's not a difficult job to remove the oil pump.

Thank you very much! That answers my main question here. I'm by no means a noob when it comes to cars (especially Mitsu's), just needed some direction to look other than the pump. I'll pull the pan ASAP and let you guys know.

[Hyperfocus]

Update for those curious about the issue- I have good and bad news.

The bad: I finally got some time off work and pulled the pan. Inside I discovered a thick puddle of black sludge which contained large chunks of a decomposing paper towel. Just to clarify, I'm a mechanic by trade so I only use red cotton rags. But while my dignity remains intact, that must mean that crap has been in there for years. I would have preferred a cracked pickup tube over this...

The good: The oil strainer did it's job well but was obviously blocked as a result. There's was just a few fine particles of bearing material in the pan and no heat marks on the rods/crank. I still plan to replace the oil pump, strainer, and bearings while I have it apart. God knows what they've been through. But on the bright side, this could have been MUCH worse.

[Boomer3000]

Congrats and best of luck!

[Alex3000gt]

Update for those curious about the issue- I have good and bad news.

The bad: I finally got some time off work and pulled the pan. Inside I discovered a thick puddle of black sludge which contained large chunks of a decomposing paper towel. Just to clarify, I'm a mechanic by trade so I only use red cotton rags. But while my dignity remains intact, that must mean that crap has been in there for years. I would have preferred a cracked pickup tube over this...

The good: The oil strainer did it's job well but was obviously blocked as a result. There's was just a few fine particles of bearing material in the pan and no heat marks on the rods/crank. I still plan to replace the oil pump, strainer, and bearings while I have it apart. God knows what they've been through. But on the bright side, this could have been MUCH worse.

Glad you pulled that pan! Better to catch a bearing issue before they spin.

Yeah it's bad news, but at least you caught it! Let us know how the bearing swap goes. Take pics if you can!

Alex