low oil pressure?

IJ.

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After seeing a pressure drop something is going on, a real pressure gauge/tester might also be an idea but most times if you see a drop with no other changes (ie: change in oil vis or leaks) it indicates bearing wear and RK usually follows.
 

mk3sons

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i have a leak that i was planning on fixing today but i got too buys :( but i Dont think its pressurized, it on the oil drain line. If i do get rod knock from this i am hopping it will be under the warrante i have for the engine until 6/18/10. But i don't know :(
 

hvyman

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Was this a jdm motor or a shop rebuild the motor?
 

CyFi6

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Dude you measured your oil pressure the first time with a mech oil pressure gauge and now you are reading the stock gauge again, of course its going to be different. Like stated its not accurate. Use your mechanical gauge for any diagnosis, the gauge in the car is for reference to see if you have any pressure, a mechanical gauge is used to diagnose issues.
 

mk3sons

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Dude you measured your oil pressure the first time with a mech oil pressure gauge and now you are reading the stock gauge again, of course its going to be different. Like stated its not accurate. Use your mechanical gauge for any diagnosis, the gauge in the car is for reference to see if you have any pressure, a mechanical gauge is used to diagnose issues.
wrong i compared the picture in the first post to new readings on the stock gauge. its now on the 20 psi line at 3k rpm if the gauge is bad enough to change ~5 psi with no actual change in pressure in one week i am going to disconnect it because its pissing me off.
 

supra90turbo

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Have you bought an aftermarket oil pressure gauge yet? All of your oil pressure woes are pure speculation if you are still using the stock gauge.
 

mk3sons

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Have you bought an aftermarket oil pressure gauge yet? All of your oil pressure woes are pure speculation if you are still using the stock gauge.
last time i checked it it was 33 psi at 3k rpm and 7 psi at idle i am going to check again when it gets warmer.
 

CyFi6

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Last time you checked what? Your stock gauge? Take everyones advice and stop diagnosing your engine with the stock gauge.
 

mk3sons

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Last time you checked what? Your stock gauge? Take everyones advice and stop diagnosing your engine with the stock gauge.
I appreciate you trying to help me but as stated i DID use a brand new mechanical oil pressure tester and i had 33 psi at 3000 rpm and 7 psi at idle. All i was saying is i don't think the stock gauge would vary by ~5 psi daily. which is why i will check again WITH AN OIL PRESSURE GAUGE.

Edit it doesn't vary it never goes up! it just goes down. hence my worrying. maybe i should but i cant help it!
 

89supracrazy

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If you dont mind I would like to jump in on this. I bought my car back in the summer and I was worried but Toyota use high volume, low pressure oil system. My oil pressure reads the same as yours. I am thinking about doing the 5mm shim on the oil pump relief valve. It is a quick upgrade. They say you get 10 to 15 on idle and about 50 to 55 max. The oil filter housing also has a relief valve and they said it was set to open at 40. Something to think about and they do have it posted here on a thread. Search for shimming the oil pump. Make sure if you do shim the relief valve in the oil pump that you dont go over 5mm. The CT turbo does not have no inlet restriction oil feed and they say to much oil pressure can make them start leaking oil.
 

IJ.

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If you dont mind I would like to jump in on this. I bought my car back in the summer and I was worried but Toyota use high volume, low pressure oil system. My oil pressure reads the same as yours. I am thinking about doing the 5mm shim on the oil pump relief valve. It is a quick upgrade. They say you get 10 to 15 on idle and about 50 to 55 max. The oil filter housing also has a relief valve and they said it was set to open at 40. Something to think about and they do have it posted here on a thread. Search for shimming the oil pump. Make sure if you do shim the relief valve in the oil pump that you dont go over 5mm. The CT turbo does not have no inlet restriction oil feed and they say to much oil pressure can make them start leaking oil.
I wish you guys would STOP posting this dribble like it's fact and that "Toyota" designed the Oil system in a 7Mgte to behave this way..... :nono:

Pressure is resistance to flow, Not enough flow = less pressure, flow in this case being volume... where does the "high volume" part of the above quote come into this huh?

What you’re seeing is a description/symptom of the issue and not “as designed”.

The M engines were never designed to be turbo charged, adding a turbo feed/leak, stupid pressure based bypass cooler and squirters into the engine outpaced the pumps in use at the time (Group A race engines ran no squirters and 360 degree grooved mains) they built a new pump with longer gears to displace more "volume" per revolution and this was a step in the right direction just not a big enough step.

The biggest factor in the low pressure at idle is the engines general condition, bearing wear both main and rods and rod side wear and Cam journals will leak like a sieve and drop the pressure as the pump struggles to plug the leaks with volume it doesn't have.

Clearenced correctly and with decent large bore full flow cooling hardware you can easily see 30>40 psi hot idle pressure.
 

89supracrazy

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I read your thread about the full flow and I really like it, but I am talking about cheap fixes. I admit I dont know alot yet about the 7m oil setup.
 

mk3sons

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I hate the idea of doing something unintended to my engine just so i can have it be within spec. However Toyota designed it the also designed it to have 36 psi at 3000 rpm and i do not. I really have no idea what to do with this engine but i hope i can figure it out.
 

89supracrazy

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No problem IJ. I am just trying to get educated everyday. I do have one question for you IJ. I read today somewhere while surfing the web, that the ct 26 turbos would start leaking around 45psi because of the seals. Is this true. They said the subaru turbos had a restrictor built inside and that is why they could run 90psi. Any info. on this.
 

IJ.

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It's not so much the pressure but the volume and the Drain's ability to clear it from the Turbo.

They use a simple labyrinth seal (think maze) so if the drain is at all restricted it overflows the "seal" and looks like a James Bond smoke screen.

When you install a restrictor it reduces the volume flowing through the Turbo and the issue stops.

This often happens when people drill the pan for a drain and put it in line with a crank throw/rod as the Oil flinging off the rod partially blocks the drain and you get the smoke.
 

mk3sons

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tested pressure again today (NOT WITH STOCK GAUGE)

28 PSI 3000 rpm :cry:
7 psi idle


i was curious so i put a clamp over one of the oil cooler line...up to 32 psi at 3000 rpm.

so what do you guys think, bearings, shitty oil cooler setup? i have no idea :(

that part that confuses me is the idle pressure being so high.
 
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mk3sons

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I suppose you don't have any issues with your valve seals leaking? I've notice that running full synth oil vs. dino lowers the pressure in my car.
not that i know of. car doesn't smoke at all. Is it possible that the pressure is going down because it keeps getting warmer out?
 

mk3sons

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The engine operates in a certain tempature range no matter the temp outside (if your cooling system is in good working order of course).
ohh ya i think i knew that. then might you have any other ideas as to why my pressure is so low?
 

mk3sons

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its holding strong at 20 Psi at 3k rpm (stock gauge. reads a little low) for a while now..still no knocking or anything. I am so confused!