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Discussion Starter #1
I do realize a lot of people have low oil pressure, but mine is barely above 0 when I am driving...are there any tests I can do to tell if my pump or sending unit is bad? Thanks guys!
 

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2JZ swapped!
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Obviously make sure its full of oil right now.
 

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Shop Tech All Around Auto
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it's at the very top of the dipstick
lol, that's a whole lotta oil....

Seriously though, most mechanic shops have oil pressure test gauges that are very accurate. They should be able to test it for you pretty easily, and you could probably get to see what the gauge is reading if you ask them.
 

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Hardtop FTW
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I have personally discovered that the pressure senders are natoriously inaccurate and have a tendency to fail. While my 88 and old 90T had accurate guages, the old pressure sender from my 91T would tell me I had 0 oil pressure at idle and under 20 while moving. I know for a fact I had more than that or my engine would have kicked the bucket. A friend of mine had shitty oil pressure to a point where his engine should have been knocking REAL loud. His oil pressure guage was bad too. An oil pressure sender from the dealer was $38.

Collin
 

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2JZ NA-T MKIII
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I agree that the factory oil pressure gauge is very inaccurate, but I too was seeing constant oil pressure under 20PSI, at idle oil PSI would sit just above the zero, if not on zero. The only time the oil pressure would look half decent was upon cold startup. I thought it might just be the gauge.. well the 7M never fell to RK, or gave me any trouble, but I decided to go 2JZ... using the same (brand new) sender unit and the same gauge my oil pressure is perfect (10 PSI per RPM until the bypass valve opens).
 

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Discussion Starter #9 (Edited)
I have personally discovered that the pressure senders are natoriously inaccurate and have a tendency to fail. While my 88 and old 90T had accurate guages, the old pressure sender from my 91T would tell me I had 0 oil pressure at idle and under 20 while moving. I know for a fact I had more than that or my engine would have kicked the bucket. A friend of mine had shitty oil pressure to a point where his engine should have been knocking REAL loud. His oil pressure guage was bad too. An oil pressure sender from the dealer was $38.

Collin
you knew that it was bad because you just replaced them and they worked after that or you actually had them tested and then replaced them?

Are these sender gauges typically known to go bad? Obviously it's the sender gauge or the pump...has anyone had a pump go bad before or is it almost certainly the sender unit?
 

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not the sender or gauge in my experience, but the port to the sensor gets gummed up, pop the gauge off, clean the end and clean the hole out a bit, and try again

40psi at 3K RPM is higher than it should be assuming you're stock as well...

pump CAN go bad, but the way it functions it's usually not going to die unless something causes it to (like lots of metal in it)
 

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Wingless by choice.
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640 Posts
IIRC 37-72psi @ 3000rpms.
Exactly, 10psi per 1000rpm = ideal. Also IIRC 4.6psi while idling, can anyone correct me or tell me otherwise that I'm wrong? Also, what weight oil are you using, a few freinds of mine use 0-30 and 5-30 and their cars are barely above 0 @ idle, and just nearer 25-30 driving.
 

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Hardtop FTW
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not the sender or gauge in my experience, but the port to the sensor gets gummed up, pop the gauge off, clean the end and clean the hole out a bit, and try again

40psi at 3K RPM is higher than it should be assuming you're stock as well...

pump CAN go bad, but the way it functions it's usually not going to die unless something causes it to (like lots of metal in it)
Every healthy Supra I've owned has been 40psi above 2500-3000rpms depending on temperature, running 20w50 oil as recommended by the manufacturer.

Collin
 

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Street Sleeper
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I always thought it was 10psi per 1000rpm MINIMUM. I run 10w40, at full operating temp my oil pressure is 15psi at idel, 30psi at 2000rpm, 40 psi at 3000rpm, 50 psi at 4000rpm this is all on the stock gauge but this is what most people have.
 

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Discussion Starter #16
not the sender or gauge in my experience, but the port to the sensor gets gummed up, pop the gauge off, clean the end and clean the hole out a bit, and try again

40psi at 3K RPM is higher than it should be assuming you're stock as well...

pump CAN go bad, but the way it functions it's usually not going to die unless something causes it to (like lots of metal in it)
this might be a dumb question...but what is your method to cleaning it? What do you use?
 

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don't remember what i used to tell you the truth, probably either carb. cleaner or brake cleaner as I always have some around

most of it will come off with a rag, dunno why the crap seemed to gunk right there though...
 
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