22re oil pressure vs gauge (1 Viewer)

[toyotaboy80]

I know hot "spec" for the 22re oil pressure is stupidly low...something like 3 or 5lbs at idle.

My truck when cold idles at the 2nd of 4 lines on the gauge(the gauge also doesnt go above this 2nd line, ever). As the motor gets hot, the needle drops to where it rests when the engine is off. When I rev the motor hot, the needle instantly comes up to the highest reading it will produce.

I took the oil press. Sender out and screwed in a mechanical gauge. The motor was hot and reading "zero" psi on the gauge whem I started the sender removal(a.k.a just below line 1, or where it sits when the engine is off) and by the time I had got sender out, the mech. Gauge screwed in and fired back up, the mech gauge read 17lbs at idle, and the gauge was midway between line 1 and 2.(aka i was slow and the motor cooled down a smidge lol)

I let the motor idle until the gauge read its hot position. At this point, the mech gauge read 9lbs. So, when the dash gauge reads zero/no psi the engine was actually producing 9lbs. As I revved the motor, the gauge went to its highest reading at the 2nd line by about 1500rpm and was producing roughly 20lbs of oil pressure. The highest oil psi I got was 70 or so lbs at 3000 rpm or less. Didnt ever make more than 70lbs.

Basically what this tells me is my engine produces good oil pressure, despite the gauge on the dash.

Why does my dash read zero when its producing 9lbs and stops climbing after the engine is in the 20+lb range? Is the sender no good or is this just the way these gauges read? How am I ever to know when I actually have zero oil pressure? Or when its not producing a reasonable pressure at cruising 3k rpm? When it starts clattering and puts an inspction hole in the block? Permanently mount a mech gauge in the truck?

Is 9lbs hot idle good? I know its above spec, but... is it good? Aka, is the bottom end in good condition or starting to get loose?

I do like the fact that at 3000rpm crusing speed I have 70lbs of hot pressure. Or maybe not. When does the oil filter bypass? Guessing at 70lbs cause it doesnt continue to build pressure? So for a lot of the time the oil is just by passing the filter in regular operation?

The oil is conventional 5w30 btw.

 

[joseywales]

I’m not an expert o the subject, but I have owned a huge variety of Toyota trucks in the 1981-1995 model years (as well as a slew of TLCs from ‘72-‘06). My experience is that ALL the mini-truck and early 4Runner gauges read really low. Your description of the gauge values is exactly the same as every single one of these trucks I’ve owned with either the 2.4 or 3.0 liter engines. It’s nice to see someone post numbers from a mechanical gauge though, to reinforce what I know (?) is going on.

As far as I know, the only way you are going to know for sure what your oil is doing is with an auxiliary gauge. Someone else may have a modification to make the factory gauge read truer, but I’ve never heard of one. I just keep an eye on the factory gauge and make sure it comes to the second mark while at cruising RPM. You may want to be more exacting than that, but I’m sort of looking for an excuse to do a 3.4 swap into my 4Runner so I just use the stock gauge and my ear to tell me how it’s all going under the hood.

 

[pappy]

My experience is that ALL the mini-truck and early 4Runner gauges read really low. Your description of the gauge values is exactly the same as every single one of these trucks I’ve owned with either the 2.4 or 3.0 liter engines.

I've owned a pair of 22re engines, and a 22r. What you are describing is just life with a Toyota. At idle the pressure looks low on the gauge, but as you found out, it's the gauge, not the engine.

 

[ntsqd]

And unless the test gauge cost more than roughly $100 or more you can't really believe it either. Cheap gauges are about as accurate as the stock sender and can be less repeatable.

Also need to know what the accuracy of the gauge is. Most are only truly accurate in the middle 1/3 of their total range. Some are "full scale accurate" but you pay for that. A fairly basic primer on gauges, as well as one source for known accuracy gauges:

McMaster-Carr

McMaster-Carr is the complete source for your plant with over 595,000 products. 98% of products ordered ship from stock and deliver same or next day.

www.mcmaster.com

 

[yotadude520]

9 lbs of oil pressure is good at idle, but I wouldn't say it's great. My truck routinely gets 25-30 PSI at idle and in between the first and second bar of the OEM oil pressure gauge. If it's a little low on oil it drops to 20. I've never seen it drop anywhere below that.

The rule of thumb for oil pressure is you want 10 PSI for every 1k in RPM'S. Considering your idle is probably set around 700-800 that seems to be sufficient. I would install a mechanical gauge in the cab so you can keep an eye on it as you're driving and since your OEM one doesn't seem to be working well.

I've had great luck with Autometer and believe it or not SunPro has been okay for me in the past. I would recommend Auto-Gage before SunPro though. I like mechanical gauges and believe they are more accurate but you can get an electric one too. If you go mechanical use a braided stainless -3AN line or copper. Do NOT use that chinsey vinyl line that comes with most cheapie gauges.

 

[ntsqd]

FWIW, that oil pressure vs. RPM RoT is engine specific. The commonly quoted 10 psi/1000 RPM originates at SBC's. An SBF's own RoT is something like 8 psi/1000 RPM. Could be that 10/1000 is good for 22RE's, I've no idea. Never looked, does the FSM have anything to say about this?

 

[pappy]

Never looked, does the FSM have anything to say about this?