86 2F 60 psi of Oil Pressure at idle

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Over the course of the last few months I’ve been plugging away at doing a bunch of work to my 60 series. Full decarb, new carb, recurved dizzy, replacing a bunch of leaking gaskets, overhauling the cooling system and just simplifying/cleaning up the bay as a whole. Brief background, 86 with 115k miles. Based on the records I got when I bought the truck the engine was rebuilt at around 60k….around 20 miles after getting an oil change the day before.

Truck is running again quite nicely, but I’ve got significantly more oil pressure now than I did prior to doing all this work.

I’ve verified the oil pressure reading with a manual gauge at the sender port under the filter, reads 59-60 psi at idle (currently set at 725ish RPM) and climbs to 70psi at 3000 RPM. I removed the high pressure bypass, verified its not stuck then put it back in. Running an OEM toyota oil filter and Rotella 5w40 oil.

My current thought is that maybe a piece of gasket fell into somewhere when replacing the side cover or front cover gaskets? Maybe a chunk is stuck in the oil pick-up? Is there anything in particular I should be looking for here? Something stupid I’m overlooking maybe? Looking for the help of the collective hive mind before I pull my oil pan off.

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OSS

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From what you’ve described as the work you’ve done on it, none of those things would affect oil pressure.
The oil pump pickup is protected by a very large fine screen mesh. No piece of gasket would affect it and even if the screen were clogged, it would be clogged on the suction side of the pump, so outlet oil pressure would drop, not rise.

See pic of oil strainer. It’s about 3-1/2” across.

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Pighead

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what is the engine temperature when you measure the pressures?
 
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what is the engine temperature when you measure the pressures?
Engine is fully warmed up, but it doesn’t change with temp. I’m not 100% sure but I think the bypass opens up at 60psi so that could explain why theres no real change in pressure.
 

fjc-man

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Good point Pighead, fully warmed up normal operating temperature of engine oil is appoxirately 325 degrees F. At those temps you would have lower oil pressure than 60 psi at idle.
 

Pighead

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you verified pressure with a mechanical gauge, are you running a mechanical gauge always or relying on the stock gauge?
the mechanical gauge on my 2F goes to 68 psi on a start (i thought the bypass opens at 70 psi) and always has done so.
 
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Good point Pighead, fully warmed up normal operating temperature of engine oil is appoxirately 325 degrees F. At those temps you would have lower oil pressure than 60 psi at idle.
Yeah, I expect it to drop when it gets warm but it’s not which is concerning.
you verified pressure with a mechanical gauge, are you running a mechanical gauge always or relying on the stock gauge?
the mechanical gauge on my 2F goes to 68 psi on a start (i thought the bypass opens at 70 psi) and always has done so.
I’m verifying it with a mechanical gauge screwed into the port that the stock sender uses. I was concerned initially because my stock gauge was pegged high, but I know that the stocker is reliably unreliable, so I confirmed with a mechanical gauge in the same location.







I know the OEM calls for 10w30 but I can’t imagine switching out to 5w40 would produce results this dramatic, right? I’ve been running rotella in this thing since I got it 4 years ago. I’ve never had this issue though.
 

Pighead

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you were concerned because your stock gauge is pegged high? doesn't come down?
isn't that the classic sign of a bad pressure sender/wire/gauge?
the mechanical gauge shows a good pressure. put one in the dash and drive it.
 
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you were concerned because your stock gauge is pegged high? doesn't come down?
isn't that the classic sign of a bad pressure sender/wire/gauge?
the mechanical gauge shows a good pressure. put one in the dash and drive it.
I was concerned because my stock gauge was pegged in the H. I verified that the pressure is high with a mechanical gauge. I’ve completely removed the stock gauge from the equation by verifying with a mechanical gauge in the location of the stock sender

The gauge read in the middle of the cluster at idle prior to doing the work and is now pegged in the H.
 

micruz60

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What's the oil level on the dipstick?
 

Pighead

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The gauge read in the middle of the cluster at idle prior to doing the work and is now pegged in the H.
Right. And you've just been cleaning up in the engine bay. An oil pressure gauge that's pegged on high and doesn't move is the classic sign of the circuit being grounded. Search that.
I think you have good oil pressure.
 
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Right. And you've just been cleaning up in the engine bay. An oil pressure gauge that's pegged on high and doesn't move is the classic sign of the circuit being grounded. Search that.
I think you have good oil pressure.
When I unplug the gauge (it’s currently unplugged) the gauge drops as low as it will go.



I guess the better question to ask is, what is a normal baseline oil pressure PSI on a mechanical oil pressure gauge? I’m not concerned with my factory oil pressure gauge currently. I’ve tested it, I know it’s good, it’s currently unplugged and out of the picture.

60psi at idle hot seems very high.
 

Pighead

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It's had a recent rebuild. I'd hope the pressure to be high.
My hot idle pressure is 24ish psi but my rebuild is 18 years old.
 

fjc-man

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You mentioned cleaning the “high pressure bypass”. To bypass a restricted /clogged oil filter? The over pressure / relief valve is accessed with the oil pan off. It’s located on the oil pump.
 

Godwin

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When I unplug the gauge (it’s currently unplugged) the gauge drops as low as it will go.



I guess the better question to ask is, what is a normal baseline oil pressure PSI on a mechanical oil pressure gauge? I’m not concerned with my factory oil pressure gauge currently. I’ve tested it, I know it’s good, it’s currently unplugged and out of the picture.

60psi at idle hot seems very high.

I think you are ok. I've had a mechanical gauge on my 2F for a long time. Normal oil pressure just off idle is ca. 60 psi, at idle the pressure will drop to ca. 40. These readings are with oil that has been run for over a few hundred miles. On a fresh oil change and with the oil cold, revving the engine to 2500 will show ca. 70 psi, but once the oil is warmed the high pressure will be 60.
 

mrboatman

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I picked up a 84 2F from a 60 back in February for my 40. When I first spun the oil pump it hit 70psi on a mechanical gauge. when I fired it up with 15/40 shell rotella, it is running 80psi and now with about 6 months on it at regular temp. idle runs 58 - 60 psi and anything off idle runs 80 psi. I was kinda worried about it but that seams to be a normal average after reading what others have responded about oil psi. So just run it.
 

RDub

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My '87 runs at 60 psig at idle with a mechanical gage, too. Seems like a good sign the crank bearings are at least not wiped out.
 

ChaserFJ60

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Did you take apart the rocker arm assembly in the head by any chance? Incorrect reassembly can cause oil pressure issues amongst other things.
I always thought the oil filter was responsible for setting oil pressure? I could be wrong
 
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Did you take apart the rocker arm assembly in the head by any chance? Incorrect reassembly can cause oil pressure issues amongst other things.
I always thought the oil filter was responsible for setting oil pressure? I could be wrong

Nope. Just set the valves.
 

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