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Discussion Starter · #1 ·
my oil pressure recently started bleeding down when the car warmed up. I have replaced everything ( oil pump, turbo, oil and filter, rod bearings etc) nothing has worked I think it has to be yhe main bearings. I am in the process of putting my car back together. I replaced the mains without pulling the crank. I hope this solves my problem. has anyone ever experienced this?
 

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1.5JZ Turbo Supra
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3,378 Posts
stock oil pressure @ idle should be 4.3 PSI & above. At 3K 40 to 60 PSI. Cold start will be 40 to 60 PSI then drop to 4.3 PSi
 

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function > form
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512 Posts
I really hope you didn't replace all that for nothing. As TaSe wrote, the pressure drops drastically once the car's warmed up. Viscosity changes with temperature.
 
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Discussion Starter · #4 ·
i have had this car for years I know all about the supras nornal low oil pressure at idle and 36psi at 3000rpm. my car runs down to about 25 at 3000 rpm and at idle it sometimes looks like 0.
 

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I also did my mains without removing the crank. I thought I was the smartest guy in the world! Oh well...

My oil pressure does go a bit lower than I'd like...around 32psi at 3000rpm when it's really hot like during a long hard highway run up hills, etc. I'm NA and don't have an oil cooler, which might help.

Any idea what your cam journal oil clearances are like? Mine are at the high end of tolerance towards the rear of the engine and I think that's why my pressure is a bit low.
 

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92 TURBO
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1,009 Posts
90beater said:
I really hope you didn't replace all that for nothing. As TaSe wrote, the pressure drops drastically once the car's warmed up.


Viscosity changes with temperature.

^ EXACTLY, it thins so try switching to a higher weight of oil. Are you using 10W-30? I found that by using Mobil 1 10W-30 synthetic over regular dinosaur 10W-30 oil my oil pressure is higher hot at both idle and 3k rpm. Try 15W-40.
 

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92 TURBO
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1,009 Posts
91supra85 said:
i have had this car for years I know all about the supras nornal low oil pressure at idle and 36psi at 3000rpm. my car runs down to about 25 at 3000 rpm and at idle it sometimes looks like 0.
^ If you have not do so already, you might want to check your pressure with a mechanical gauge screwed into the stock oil pressure's sender hole to see how it compares with the stock electric sender/gauge. Just an idea before you go any further. I don't think the stock system is very accurate.
 
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