Low oil pressure all of a sudden

[allenms240]

ey there guys,
I am having a little t rouble with some oil pressure on a rebuilt sr20det.
I rebuilt it and got about 400miles on it currently. After initial warm up, the oil was changed, and again after 50miles. The oil in there now has 350miles on it. The other day I went ahead a installed my manual boost controller and have finally been boosting the motor. The other night I noticed that after boosting hard, the oil pressure was pretty low. I was running about 20psi at 2krpm and about 9psi at idle. This was the first time it has run this low, up until now I had acceptable values. The gauge sender is an electric GReddy unit so I don't think that is the problem. The next morning I started the car and was reading the usual 80ish psi for cold start.
The oil pump was replaced (bought of a user who has about 500miles on it from new), the oil sump o ring was replaced in the rebuild, and an ISIS oil pan is on the motor, so I don't think it is a problem with the sump.

Could it be this conventional oil is breaking down early because of the heat the motor is causing? I am using 10w-30 valvoline conventional. In a few days the amsoil 10w-30 will be here and that is the synthetic I will be using.

Any ideas?

EDIT:
I changed the oil today to Amsoil 10w-30 and slapped on a new oil filter. I went to get some food, the car warmed up, all pressures looked good. After I left the food joint, the oil pressure was as it was before, it's low and it's worrying me. I got to school and shut the car off and waited for ten minutes. I then started the car and the oil pressure was fine. I was reading acceptable oil pressures. I'm sure that if I leave the car on for over a minute though, the pressure will drop. So, what could be causing this low oil pressure? Need some ideas fast because it's my daily driver.

Allen

EDIT: The car drive fine, no exterior oil leaks, only low pressure. I'm scared to go above 3k though.

I know there is the oil sump o ring, an o ring on the oil pump to block, and 2 gaskets on the filter assembly. Are there any others seals I don't know about?


EDIT: The gauge is functional. I tested it with an analog gauge and getting the same results.


I plan to order all new gaskets/o rings, I just need to know what all there is int he oil system.
So far I have oil strainer o-ring, the 2 o ring/washers on the filter assembly, and the o ring between the block and the timing chain cover. What else is there?

Also, it seems to be a seal, not the actual pump, right?

[Razi]

Probably some sort of leak somewhere.
It's probably a pain in the a** but I'd double check all the small o-rings.

[blkvrtswp]

11 psi @ idle is the normal reading once oil is fully warmed on an SR20DET.

[allenms240]

I know the correct values haha, I am just not getting them.

I went ahead and bought new seals to replace (the ones I can think of anyway). Then later on in the date I decided to replace the pump for good measure. So I bought one. We'll see how it goes when the parts come in.

[s13-t]

My motor did the same thing. Turned out that the pick up was covered in excess rtv. Have you dropped your lower pan to take a look? If its not that o would throw some Lucas oil stabilizer in it. Pressure would go right back to normal.

[allenms240]

I could try the stabilizer, but I really don't think an additive would fix this problem.

I will be inspecting all components next week when I start working on it.

[IanS]

Sounds like you have something floating around in the bottom of your pan. Could be RTV, or chunks of gasket. I have seen it way too many times. If you get a little over friendly with the liquid gasket, chunks break off and float around the pan. They rarely drain out with a change. They get sucked up into the pickup screen until the pressure drops. When you shut the car off, they fall out.

I also had similar issues with dropping oil pressure after I lost the strainer off my pickup tube. It was damaged and broke off. What gen SR is this? The S13s have a badly designed tube that tends to fail. The S14 SR part was revised and can be installed on S13 engines without modification.

I actually did a write up on this swap. how-to-sr20det-oil-strainer-pickup-tube ... kup%20tube

[krash]

el move-o'd to el essar forum.

[allenms240]

Thanks krash, I just though it'd get more traffic in general. This ismy first SR post with the motor

Anddddd...
It was the sump o-ring!!!




Or so I hope. I pulled everything off (crossmember, both oil pans, and about to proceed to the oil pump. I am going to go ahead and replace it for good measure.

So happy I found it.

Now I only have a problem with oil in cylinder three I need to figure out.

[OM3GA]

Please replace your oil pickup tube with an S14 SR one... Larger opening and uses a full gasket instead of an o-ring.