Low Oil Pressure

[surfer1158]

hey my oil pressure has been hovering above the red low just within the white normal line. when i accelerate it drops down even further and when i let off the gas it comes back up just a little but its still pretty low. I only hear the lifters a little when it starts up but other than that it sounds fine. what could be the cause? and what options should i try? There is currently seafoam running through the gas right now.

 

[TeckNine4]

Mine has low pressure all the time as well,,, I think its bad valve seals??:exp:

 

[smtcapecod]

Sea foam in the gas won't do anything for oil pressure.
You can try one of the ring-sealing cans of snake oil. But if it isn't smoking (out the exhaust) then I'd just step up on the viscosity chart a bit to 10W40 or 5W-50 synth.

If the seals/rings were worn you should see and smell the oil combustion via the exhaust.

I have no idea how one could check the oil pump for pressure & volume rather than just working/broke without removal.

 

[Maniak]

The most important question here is do you really have low oil pressure? The factory gauge using the factory sending unit is just an off/on switch. 5 psi and it shows normal.

If the sending unit/gauge is working correctly and your getting a fluctuating gauge then there is an electrical issue. Either the wire going to the sending unit, the voltage in the cluster or the gauge itself.

Check the fake oil pressure thread for more information about this.

until you know you really have low/no oil pressure I wouldn't do anything drastic.

~Mark

 

[Jack Flash]

like Maniak suggested, I would check the 'actual' oil pressure with a manual guage.

from wasting my formative years in the junk yard and owning an awful amount of 'junk' vehicles in my life, I would tend to think you have serious wear in your main bearings and/or rod bearings.

pressure dropping when you rev up and then increasing when you let off the throttle suggests excessive wear on the mains/rods. the thrust main bearing is most likely worn, allowing the crank to walk back and forward, giving these strange readings.

check the oil pressure first.

...jjf

 

[aldive]

If you are concerned about the oil pressure, hook up a "real" oil pressure gauge and check it.

Good luck ...

 

[TeckNine4]

Really? A real oil pressure gauge? where you hook it up at?

Some goo ol' georgia boy told me it was the "journals" on the crankshaft...

WTF

 

[Maniak]

Oil pressure reading can be taken from the same port the factory sending unit is connected to (drivers side of the block, near/behind the power steering pump). Either T off it to run both or just disconnect the factory one and hook up a mechanical gauge. You can check your symptoms w/out driving.. If your really dropping pressure when you bring up the rpms then you may really have the problem. If readings are different when you use the mechanical gauge then you need to look into installing one perminantly(sp?) or at least modifying your stock gauge/sending unit combo to move with the oil pressure.

~Mark

 

[surfer1158]

hey guys got a little info that might help today. Okay so we had a cold night here in denver, about 10 over night and about 20F when i started it up. When i started it up and for about a couple minutes the oil pressure was almost perfectly in normal, then it seemed as i drove it more and it heated up more the oil pressure dropped back down again just inside the normal white line. and im kinda noticing a little more ticking...but its still very very faint, u have to listen when its perfectly quiet.

 

[mechjames]

the stock sending unit is just on/off. change the sending unit. it seems like its failing when its warm

 

[2doorsplor]

pressure dropping when you rev up and then increasing when you let off the throttle suggests excessive wear on the mains/rods. the thrust main bearing is most likely worn, allowing the crank to walk back and forward, giving these strange readings.

check the oil pressure first.

...jjf

What kind of damage would occur if there is excessive wear on the mains/rods?

 

[Alan_V]

The first thing that pressurized oil does after going thru the pump, is report itself to the sending unit. If you have low pressure on a live gauge where the oil sender is located, you have a bottom end problem (pump, relief valve, bearings, etc.). You can also try an FL-1 factory filter (I get mine at Pep Boys). There are internal pressure relief valves in aftermarket filters that may not be up to the same standard as the factory filter.

As has been mentioned. The electrical sending unit is subject to the inaccuracy of electrical components when temperatures change.

This may be difficult at this time of year in Denver, but use and ohmeter on a 70 deg. day when the engine hasn't been started. Get the resistance spec for the service manual and measure resistance of the sender. This is a common starting point. If your manual gives a hot spec, then start it and get it full warm and take the same reading. If okay, you have 2 choices. Get behind the dash and find the "other end" of the wire and make the same hot test. Now you've checked the entire circuit. If it's to spec., then get a test with a real pressure gauge.

As a note, the oil going to valve seals and rings isn't under pressure. Typically both of these components are lubricated by what I refer to as "splash." For the valve seal, oil is pumped to the head and out into the valve area. While it is directed towards the valves and seals, when it gets there it's not under pressure.

It's not a bad idea to try a thicker oil, but you have to have a live gauge to see exactly what the change in pressure is.