So im having an oil pressure problem, it sits at the first quarter mark. This is a list of what i've looked at or fixed in the past week with no results
Changed Oil Pump
Oil Filter and running 10w-40
Cleaned pickup line and checked rod bearings(Looks fine)
Sprayed Brake cleaner on sending unit

Could it possibly be the rings goin bad?? BUT it doesnt smoke so how would that make sense?

 

Have you tried a pressure gauge yet to get the actual pressure?
My dash gauge has always read low at idle and so did my first and second gen Runners.

 

these stock gauges suck...mine sits reeeeal low at idle..

 

mine does too. i had 206,000 miles on it and would go thru 1 quart of oil every 1k or so. i have a new motor and it reads the same as before.

 

check with an actual mechanical gauge and then check the specifications as to psi at various speeds and temperatures.

 

10psi every 1000rpm is a general rule of thumb...and remember, too much oil pressure is a bad thing...

 

- Why do you think that is too low ???
- The oil your using is too thick, especially when cold.



Fred

 

FredTJ i've ran 10w-30 and 5w-30 with the same results, thanks for all the replies!!!!!!!!!!! Im hopeing its not a problem the truck seems to run fine it just sits really low. I'll try to get my hands on a gauge to get a true reading. Do you think by chance it could be the sending unit clogged and just not getting enough oil and thats the reading it sends? Thanks again you guys are great im glad im not the only one that faces this day to day mystery

 

10 PSI per 1000 rpm's is a rule of thumb, so to speak... a guideline you can use to figure if your pressure is within spec. That doesn't mean that your oil pressure should be 1/100 of your RPMS- 700 rpms= 7 PSI, 1400 rpm's=14 psi, etc.
Engines are built differently and as such, what becomes more important is that you have pressure, and not too much, moreso than what the actual pressure is. Overall, as long as you have more than the minimum pressure, pressure increases with rpm's and the pressure doesn't exceed the manufacturer's specified limit, you're fine.

Over about 70 PSI in the common engine can cause oil to get behind the crank and rod bearings and cause them to spin which in turn blocks the oil passage cutting off oil to the bearing and it will soon gall and sieze.

 

and too much pressure causes more friction against rotating parts...faster wear and loss of power...

 

Why would that oil be too thick? I've run 15w-50 for years. I did an entire rebuild 2 years ago and had ZERO cylinder wear...I mean ZERO as measured by micrometer....

?

 

I had the same problem and bought these from Schucks. Turned out all it was was the stock gauge. The gauges look good in the truck too!!!

http://shop.oreillyauto.com/productd...goryCode=3342C

 

How many miles on the engine? Engine oil pressure will drop over time as bearings wear.

Is it staying at the first mark? Or just at idle? It is normal for the gauge to read even slightly below the first mark at idle.

Verify the actual pressure - as one poster already mentioned.

Piston rings won't affect oil pressure, as stated above, more likely to be worn bearings.

You could try running a thicker oil or even a mono-visc oil like SAE30 (depending on your climate) to see if that brings pressure up a bit.

 

It's not and the statement "especially when cold" is just wrong.

 

they want 57 dollars at Napa for a new sending unit, i'm gonna wait untell i can get my friend over today or tomorrow with his gauge to get an actual reading.
Keily, what im i looking for when looking at rod bearings? i looked at them and they looked fine, almost new? the motor has around 130k i believe on resurfaced head

 

No, the "especially when cold" is more than correct.
Why in the world do you think that statement is wrong ?
Post up the reason so we can see exactly what you don't know
about oils/pressure/flow etc.

You are aware, aren't you (though it seems not) that even at 70*F, 0 "weight" oil (as in 0W-30) is still too thick to flow enough.




Fred

 

Dude, you still haven't answered the question which is "WHY do you think the pressure is too low" ????????

Mine sits just barely "off the low peg" at idle and just at the first mark or a touch above at 2000-3000 rpm (once the oil is up to temperature) and I know that my oil pressure is correct as I've measured it.
BTW I run 5w-20 synthetic.

The only way to know if it's low or high is to measure it and, you need two gauges to do that. You need an oil pressure gauge and an oil temperature gauge.
As already mentioned, you are shooting for 10 psi / 1000 rpms once the oil is up to operating temperature which takes longer than to get the "engine" up to temperature.




Fred

 

I don't get it.

10W-40 is the same viscosity as 10W-30 when cold.

 

Yep, you get it.

 

Sorry Fred, but a 10W40 oil is not too thick. I don't have time to pull mine out of my pants for you tonight... maybe tomorrow.