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I just put a mechanical wide sweep oil pressure gauge on my 03 Tundra V8 to monitor the true reading at idle. I goes from 75 lbs at highway to 15 lbs at idle. I have a loud tap, that started two months ago when starting it up cold, for just a minute when tempature is less than 47 degrees.The tapping sound is like two rocker arms both having a 1/4" gap clearence.
My is still under warrenty and Toyota is giving me a run around.

My 1st complaint was the factory gauge with lines is reading lower than normal at idle [1st line from bottom on gauge],Answer-:td:See no leaks and gauge responding correctly.

My 2nd complaint was truck tapped when starting cold. Answer= :td:See tapping CAN BE normal till fully warm due to Hyper Tention Pistons
I bought truck new and the tap has only been the last two months.
The dealer does hear a small tap all the time, only when its in drive.

They has the truck again one day this week,but could not check oil pressure, because their only gauge in shop was broken.That is why I put my own gauge on.

What should be the lowest normal oil pressure reading at idle?
Thanks in advance Al
 

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I have a mech. oil pressure gauge in my truck too. When its warm and idling it'll stay between 15 and 18 psi. When i start it up in the morning it will run around 70-80 and easily hit 100psi or over, if i mash the throttle when the motor is still cold. When's the last time you changed or checked your oil? I changed my oil the other day and noticed that it now has better oil pressure then it did before. It also depends on what ACC. you have on. I have a low oil pressure warning light that comes on when the oil pressure goes under 18. I noticed it would come on when I turned my headlights on, heat on high, and whatever else.
 

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hi, wow i have no idea what you have.
i have a oil pressure guage. it looks like the fuel guage.
when i start it it goes a little higher than 1/2 than, when it heats up or when the tundra is warm, it drops slows down to 1/4 and as i drive it's highest it ever goes is a very little past the 1/2 way mark. it used to before all my mods, go from 1/4 to 3/4. but since all my mod's the pressure has gone down.
which from what i have been told is good.
i wish i knew what other type of extra guage you guys have. but all i can tell you is what the tundra comes with.
good luck, if that helps,
gorilla
 

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I just put a mechanical wide sweep oil pressure gauge on my 03 Tundra V8 to monitor the true reading at idle. I goes from 75 lbs at highway to 15 lbs at idle. I have a loud tap, that started two months ago when starting it up cold, for just a minute when tempature is less than 47 degrees.The tapping sound is like two rocker arms both having a 1/4" gap clearence.
My is still under warrenty and Toyota is giving me a run around.

My 1st complaint was the factory gauge with lines is reading lower than normal at idle [1st line from bottom on gauge],Answer-:td:See no leaks and gauge responding correctly.

My 2nd complaint was truck tapped when starting cold. Answer= :td:See tapping CAN BE normal till fully warm due to Hyper Tention Pistons
I bought truck new and the tap has only been the last two months.
The dealer does hear a small tap all the time, only when its in drive.

They has the truck again one day this week,but could not check oil pressure, because their only gauge in shop was broken.That is why I put my own gauge on.

What should be the lowest normal oil pressure reading at idle?
Thanks in advance Al
Not being there to hear in in person it is hard to diagnose but your tapping sounds to me like a cracked header - pretty common on our trucks.
 

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I know the old rule of thumb was 10 psi per 1000 rpm. The oil pump is driven off of the crank I believe. I have had many cars that will tick, ping or knock when you fire them up cold and then go away. The tight tolerances in today's motors will do that until the metal warms and the oil starts to pump. now if it knocks when warm you have a issue.
 

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When idling my oil pressure guage has always been near the L mark on my 2002 Tundra. I use 5W-30.

Scoob
 

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Yes that is where mine is too. But to be honest that gauge is just about worthless.
 

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2015 Toyota Tundra DC SR5 5.7L
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According to Chilton:

Oil Pressure Specification
V8 Models
At curb idle: 4 to 5 psi
At 3000 rpm: 43 to 85 psi

It doesn't specify, but I would assume that these numbers should be read with new 5W-30 motor oil, a new filter, and warmed to standard operating temperature.
 

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2015 Toyota Tundra DC SR5 5.7L
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I have a mech. oil pressure gauge in my truck too. When its warm and idling it'll stay between 15 and 18 psi. When i start it up in the morning it will run around 70-80 and easily hit 100psi or over, if i mash the throttle when the motor is still cold.
Where did you install the mechanical gauge? These numbers are higher than that posted by the Chilton's and Haynes manuals. And why would you "mash the throttle" on a cold motor?

When's the last time you changed or checked your oil? I changed my oil the other day and noticed that it now has better oil pressure then it did before.
What do you mean by "better"?? Higher than the above readings? Lower?

It also depends on what ACC. you have on. I have a low oil pressure warning light that comes on when the oil pressure goes under 18. I noticed it would come on when I turned my headlights on, heat on high, and whatever else.
I would argue that you have a "warning light" that is pointless as it has too high of a lower set threshhold. Simply turning on vehicle accessories should not trigger an oil pressure warning light.
 

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When my Exhaust manifold cracked it sounded exactly like a ticking valve. It was cracked at the weld for the flange ant the front driver side exhaust port. It would quiet down after it warmed up but would always be there in the background. 15psi sounds right for idle with thinner oil, especially here in my neck of the woods (warm weather).
 

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Discussion Starter #11
I always change the 10-30 oil more frequently than recommended. I always have forced Kerosene
into the oil pan with a suction gun and let it drain out completely. After doing it three times,the inside the pan is squeeky clean and the new oil stays clearer much longer. In fact its hard to see the oil line on dip stick.
The dealer questioned me on what brand filter I used. I always used Fram,but I tried a toyota brand and found the level on low and high reading was 1/8" higher during warm up only and also when starting cold, the pressure went up over 3/4 mark on factory gauge, until operating tempature was normal,then started to drop swiftly
 

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2015 Toyota Tundra DC SR5 5.7L
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so is low pressure better than high on the gauge?
Strictly speaking, neither. Oil pressure is a function of volume, pump speed, viscosity, and flow. Low oil volume = decreased pressure. Flow restrictions = increased pressure. What is important is to be aware how, when, and why the indicated pressure fluctuates. If you're at 2,500rpm driving down the freeway and your pressure indicator is at the low end, something is wrong; you either are a quart (or two) low, or you have a potential oil leak somewhere.

Also, note that the 2UZFE oil pumps are shaft driven, so as RPMs increase, all else being equal, the pressure (indicated) will increase.
 

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Strictly speaking, neither. Oil pressure is a function of volume, pump speed, viscosity, and flow. Low oil volume = decreased pressure. Flow restrictions = increased pressure. What is important is to be aware how, when, and why the indicated pressure fluctuates. If you're at 2,500rpm driving down the freeway and your pressure indicator is at the low end, something is wrong; you either are a quart (or two) low, or you have a potential oil leak somewhere.

Also, note that the 2UZFE oil pumps are shaft driven, so as RPMs increase, all else being equal, the pressure (indicated) will increase.
I agree. For what it is worth, most people on this site with the factory guage have reported indications around 1/2 scale at idle after a few minutes on cold start up and 3/4 scale when driving (2000 - 2500 RPM) when cold. When the engine reaches normal operating temperature, the readings reported have been around 1/4 scale at idle and around 1/2 scale when driving (2000 - 2500 RPM). I have observed similar readings on my truck. I believe there was a TSB on early models regarding replacing the oil pressure sender for low pressure readings but I do not have the TSB number or details.

I am convinced that these are 300K mile engines with 100K mile transmissions (at least on the 2000 - 2002 transmissions). I may be biased since my transmission lost O.D. at 105K on a 2000 model, but this is an oil pressure thread not a tranny thread.
 

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I agree. For what it is worth, most people on this site with the factory guage have reported indications around 1/2 scale at idle after a few minutes on cold start up and 3/4 scale when driving (2000 - 2500 RPM) when cold. When the engine reaches normal operating temperature, the readings reported have been around 1/4 scale at idle and around 1/2 scale when driving (2000 - 2500 RPM). I have observed similar readings on my truck. I believe there was a TSB on early models regarding replacing the oil pressure sender for low pressure readings but I do not have the TSB number or details.
You pretty much described my gauge's operation on my 06
 

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Sorry to dig up an old thread, however, this information (below) may help others with the same issue.

I believe there was a TSB on early models regarding replacing the oil pressure sender for low pressure readings but I do not have the TSB number or details.
2000-2003 Toyota 4.7L Tundra & Sequoia Oil Pressure Guage Reads Low: Engine Builder

Some customers with Sequoia or Tundra vehicles with 4.7L engines may encounter an oil pressure gauge that reads abnormally low at idle. An updated oil pressure sender has been created to address this condition.



Affects 2000-2003 model year Sequoia and Tundra vehicles produced BEFORE the VINs shown below:

MODEL STARTING VIN

Tundra 5TBBT44112S314095

Sequoia 5TDZT38AOZS117526

1. Verify that the NEW parts are built after the Manufacturer's Sender Case production date, as identified below.

2. Replace the Oil Pressure Sender.

3. Verify proper operation of the Oil Pressure Gauge.
 

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What does the Owners Manual say about oil PSI? Yes it speaks of this and all of my trucks are the same, as long as you have oil PSI it's all good at idle! It explains the various conditions and where the needle should be at different RPM's!:D
 

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700P.

My gauge is wired into where the stock gauge reads from down by the oil filter, And so is the warning lite. The warning lite is not pointless in any means, I don't know what you mean by that? Anytime my oil pressure is below 15psi the light will come on, the gauge is also wired into a water temp sender, over 220 degrees the light will come on, And its also a shift light. On a mech. Gauge, the pressure will go down with the more acc. you have on. When you have your headlights on at idle, the idle of the truck goes down slighty, because the alt. is now " working some " I guess you could say. You wont see the difference with the OEM gauge but you in an aftermarket gauge. I just put a sub in my truck and if my truck is sitting there idling and I turn the stereo up, the warning light will barely light up every time the sub hits. Same with my aftermarket volt meter. Every time the sub hits, it the needle jumps. It jumps with the turn signals too, but the oem gauge doesn't move.


Another thing I have noticed is the water temp gauge in our trucks. I have a aluminum radiator and two electric fans that run off a fully programmable dakota digital fan controller. The sender for the electric fans is tapped into upper rad. hose. In the mornings I been watching both of them. The oem gauge is almost to where it should be( normal operating temp) and the coolant is only 110degrees. At 220 degrees the needle has barely moved over the normal operating temp spot. The sender itsnt off ,because it says the same exact temp the gauge in the radiator says.
 

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I have the exact same truck as you. When I first got the Tundra I fretted about the (apparent) low oil pressure at idle. The dealer was going to replace the oil sender but I found out they just calibrated the sender to read higher at idle so I said forget it. They had no intention of doing anything about the actual oil pressure: just make it so the needle sat at a higher reading at idle (duh).
They had no worry about the oil pressure so I decided I didn't either. In 7 years I've had no problems.

George60
 
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