High Oil Pressure

[SR.GRINGO]

I just took delivery of my new 94 80 and I am concerned that my oil pressure is too high. At idle such as at a light the gauge is at the 1/2 way mark, speeds around 35mph at the 3/4 mark. Freeway speeds it hits the mark at the very top. If I floor it the gauge also tops out.. Please help me with some solutions--I am sitting in a hotel room using a tv/internet keyboard system----it sucks!


Things done today
replaced the Toyota radiator with a new OEM
changed the plugs/wires/distributor
changed the oil with valvoline 10w40--8 quarts
new brake pads from 100 series


I am in AZ right now and tomorrow planning on driving 1000 miles to Mazatlan Mexico. Your help is really appreciated.

Jason

 

[mongoman]

SR.GRINGO ,what is the weight of the oil you are using? try 5w/30......ALSO a guage indication error or calibration shift is a real possibility on your instrument..... Get a direct reading from the port that your oil pressure transmitter is screw in-to,and compare it to specs. If no relief , the bypass check ball located under the oil filter could be stuck closed and not bypassing. but thats a reach!!!

 

[e9999]

yes, that is much higher than mine
too high a viscosity comes to mind, or a plugged line?
E

 

[RavenTai]

Congratulations

You should have 4 marks, call them 0, 1/3, 2/3, & top, mine goes to just over 2/3 (relief pressure) when started cold (oil is thick) and stays there no mater what until it warms up, after warming up it will be at the 1/3 mark at idle and climb as rpm increases until it hits just above the 2/3 mark again and then holds there (relief pressure)

Either your oil pressure relief valve is not opening early enough or it is a bad indication, since yours idles at the 1/2 mark (also high) I would guess that it is indication problem,

but you are about to drive 1000 miles in an new-to-you vehicle, and the relief valve is easy to replace as long as you can find a Toyota dealer with the parts, you will need a new plunger, spring and seal, IIRC all three parts were cheap, total less than $10? Will take less than 30 min, worth a try IMO just for the piece of mind

On the front USDS of the motor there is an extension of the timing cover near the crank pulley, inside this extension is the oil pump, on the back of the extension the power steering pump,

Looking from the bottom of the truck on the far USDS of the extension is a very large hex head it faces partially to the USDS and partially down, remove the hex head and some oil (less than 1 qt) then a spring and then the plunger will come out, you may need a pick or your pinky finger to get the plunger out (note orientation of plunger) put in the new plunger, then new spring, and then old hex bolt with new seal, torque to 36 ft pounds


See if it changes, if no change I would bet on a bad indication, you could also get a new oil pressure sender (no idea on $, contact Dan, probably expensive) it lives under the exhaust manifold near the front of the motor

Good luck

 

[SR.GRINGO]

Is 10w40 too high of a viscosity?

 

[SR.GRINGO]

Thanks for the quick and detailed responses. I will try Tucson Toyota in the Morning for the plunger, spring, and seal. Where is the port the oil pressure transmitter is screwed into? I hope a faulty gauge is the only problem---it sits at the 1/2 mark--when I apply the gas it goes up wit the accelerator---let off the gas the gauge drops to 1/2......

 

[e9999]

is it very cold out there by any chance?
could be adding to the reading, but probably not that much
E

 

[lurker]

Is 10w40 too high of a viscosity?

I run 15w40 and I can barely hit 3/4 when the oil is cold at 5 mph (35f degrees, 0c). After I'm warmed up I can barely hit 2/4 at 70 mph but drop down to right above 1/4 at idle.

Please remember that I have 250,000 miles so I should read lower than average.

BTW you said you changed the oil, so I assume that you also changed the filter? That would be too obvious.

 

[SR.GRINGO]

I did change the filter as well. What will high oil pressure do to the engine?

As Raven suggested above I will buy the spring assembly.

I will also find somewhere that can measure the oil pressure from the port.

I do not have internet access where the Cruiser is located.

Any other ideas come to mind?

Thanks,

Jason

 

[e9999]

the thing about oil pressure being high is that it could be a good or a bad thing I guess.
High pressure suggests the oil pump is working fine, a good thing, whereas it could also mean that some of the oil "passages" are obstructed, a bad thing. The latter seems somewhat unlikely to me, however, unless it's some major discrete thing like a bad filter or something.
E

 

[SR.GRINGO]

It is cold to me here---high 30's low 40's. The shop I had change the oil put on a framm---I have a Toyota filter that I could change it with.....

 

[MoJ]

For what it's worth -

If I go by Raven's description of the gage - there are four marks, dividing the range into 1/3's. My 94 consistently stays within the upper 1/3 of the gage. At warm idle it's at the bottom of the top 1/3, at speed/during acceleration it's at the middle of the top 1/3. I've never seen it get much higher than that. Never worried about it. In fact I worried more about the pressure on my 91 which stayed in the lower 1/3.

 

[Rich]

The very first thing to do is to measure the oil pressure with a mechanical gauge. Then you will know what is reality and can determine what to do next. While the problem may very well be the pressure relief valve, it doesn't make sense to replace it without first confirming that your actual pressure is too high. One possibility is that your pressure sensor is shot. Again, you need to check with a mechanical gauge first.

Regarding the Fram oil filter: some of their filter products are of reputed very low quality. If I had a choice between Toyota and Fram, the Fram would be in the trash.

 

[RavenTai]

Not sure a restriction would change oil pressure that much, the restriction would just cause the relief valve to open further and port the excess oil that could not get past the restriction back to the inlet of the pump, the parts after the restriction would get less oil

Mineral (dino) 10w40 is ok for 30*F but not to much colder , since you are about to drive a long way and into a warmer climate it is probably a good idea, same as above relief pressure should not change that much with viscosity

The oil pressure port and sender is under the exhaust manifold hiding under a head shield just above and aft of the A/C compressor near the front of the motor

For what it's worth -

If I go by Raven's description of the gage - there are four marks, dividing the range into 1/3's. My 94 consistently stays within the upper 1/3 of the gage. At warm idle it's at the bottom of the top 1/3, at speed/during acceleration it's at the middle of the top 1/3. I've never seen it get much higher than that. Never worried about it. In fact I worried more about the pressure on my 91 which stayed in the lower 1/3.

Hmm, I wonder if the gage is calibrated different on the 94 vs 96?

 

[tucker74]

For what it's worth - the guage in my '93 behaves the same as MoJ described above...and has ever since I've owned the vehicle. Mine will even reach the upper bar under hard acceleration - M1 0W-40 with Toyota filter...asked about it here when I purchased the truck and haven't worried about it since. Maybe I should mechanically check mine as well?

Tucker

 

[e9999]

on my 97 with 10/30 dino, cold the pressure will read around the 2/3 line when starting up. As soon as it warms up it goes down. When hot, at idle I am around the 1/3 line but at 2000 rpm I would go back closer to the 2/3 line, although maybe not quite all the way there. IIRC this is OK per the owner's manual.
All from memory...
E

 

[MoJ]

IIRC - the owner's manual says that anywhere in the range of the gage is OK.

 

[RavenTai]

hmm starting to think the 93/94 gage might be diffrent from the 96/97

 

[cary]

I'm going to second Raven Tai's original thoughts that it is either a bad sender or bad relief valve.

 

[Cruiserdrew]

The very first thing to do is to measure the oil pressure with a mechanical gauge. Then you will know what is reality and can determine what to do next. While the problem may very well be the pressure relief valve, it doesn't make sense to replace it without first confirming that your actual pressure is too high. One possibility is that your pressure sensor is shot. Again, you need to check with a mechanical gauge first.

Regarding the Fram oil filter: some of their filter products are of reputed very low quality. If I had a choice between Toyota and Fram, the Fram would be in the trash.

Word. Check the pressure before doing anything else. My bet is that your pressure is normal. 80 series oil pressure guages and readings are wonky-really little better than an idiot light.