Oil pressure issue/question. (1 Viewer)

[mochosla]

Hi guys. I bought a 1992 Toyota truck from the original owner. I've been chasing this guy for a long time and he finally sold it to me . Well, when I drove it home, the oil pressure dropped significantly at low RPMs after the truck reached operating temp. As soon as I accelerate the pressure goes up to the middle of the gauge. The oil level is fine but the truck does have 220K miles on it. I got the truck for a very good price so I'm not overly concerned with the issue but I do have a couple of questions:

1) I heard that I can exchange the oil pump with a high-pressure pump. Is that accurate?

2) Since the engine is not making any odd noises, can I just drive it as is and not worry about it until the engine dies or has other problems ralated to this? The owner tells me that it has done that for a while with no issues.

BTW, the truck has the 6 cylinder 3.0 engine.

Thank you.

 

[Mudder]

I'd put a mechanical gauge on there to check for oil pressure.

 

[mochosla]

I'd put a mechanical gauge on there to check for oil pressure.

Good idea. Thank you.

 

[PhrogsPhorever]

How low is low? Gauge bottoms out or lower quarter of the gauge?

My 22RE drops low at idle once warmed up, so did my 3B, and my 1HZ

 

[pappy]

Mine also drops down at idle. It was real low before I put in a "new" gauge. I would guess it's a gauge issue. Like Mudder said, install either a mechanical gauge, or an electronic gauge.

 

[PhrogsPhorever]

Yeah, the Toyota oil pressure gauge is a POS.

 

[mochosla]

How low is low? Gauge bottoms out or lower quarter of the gauge?

My 22RE drops low at idle once warmed up, so did my 3B BJ70

Maybe halfway on the first quarter if not a third.

 

[PhrogsPhorever]

That's about where mine sits at idle, likely not an issue.

I plan on replacing my oil press and water temp and putting them where the inclinometer doo dads are

 

[KLF]

The factory temp gauge in mine was worthless, it would sit at cool for a few minutes, them suddenly pop up to midway and never move.

Autometer gauges for the win, mechanical if you can. Wish I could figure out how to install them in my 3UR in the Cruiser.

 

[PhrogsPhorever]

Typical day at a red light

 

[vipergrhd]

Just to add what others have suggested, get the oil pressure check with a mechanical gauge hot and cold. I have never heard of a high pressure or high volume pump for a 3.0l I have owned my truck since new and on a hot day it will get close to the first line, since you just got the truck I would find out when was the last time the TB and WP was replaced 3.0l engine is an interference engine meaning it will contact piston and valves if the TB gives way I would also remove one of the valve cover and see if there is any sludge build up if there is it could mean that some of that junk is getting sucked into your oil pick up screen and causing a partial clogged. Nice to see these trucks still around.

 

[ferg]

Another thing, try running straight single weight oil and see what happens. Often multi-weight oils will exhibit this low pressure characteristic. You're in L.A. so straight 30wt or 40wt would still be quite acceptable.

 

[2ndGenToyotaFan]

I would not even be worried. PSI at +/- 3000 RPM's is supposed to be 50 or 60, and only around 5 at idle.

 

[Prairie Swamp]

Not really relevant to the thread - but 4 cylinder Mazdas of the 80's and 90's vintage ran essentially no oil pressure at hot idle. The idiot light switch was set at about 1 PSI, verified via good mechanical gage. And I had these do 300K without a drop of oil consumption.

Just a data point - probably has everything to do with how the oiling system is designed. Very possible that Toyota - especially in a truck engine - prefers more oil pressure at idle. But I "think" it's more about flow than pressure as far as the moving parts are concerned.

 

[mochosla]

Typical day at a red light

View attachment 1552467

Yup. That's my truck.

Thank you.