Low oil pressure at idle

[bicycleagent003]

My oil pressure never registered zero while running, but it did increase noticeably after I installed a new valve cover gasket, new spark plug tube seals and a new PCV and grommet. I was surprised at what a difference those items made to oil pressure as reflected in the movement of my needle while driving. If you don't know when those were done, it's probably worth doing anyway. And it's fun.

 

[Howard705]

Those should not affect the pressure of the oil. Only the leaking of unpressurized oil draining back.

 

[stevesoutriding]

This is where my 93 idles after warmed up. It does climb to the halfway point as I add throttle. Believe I used 10w30 castrol on last oil change.

 

[jbee]

I had the same issue on my 96 and my 97 when I used the ‘fancy oil’ full synthetic, Mobile 1, etc.
.Also developed a couple oil leaks with those types of oil. When I went back to regular Dino (following advice of Tools and Inkpot) the pressure got normal.
nothing against those oil‘s, I run them in my Hondas and Chevys and Acuras and they are fine.
I have heard that oversees this same engine was spec’d with different oil, thicker, and that the US engines have the thinner oil recommendation for gas mileage/mpg/EPA considerations. Have not confirmed that. My motors run better with the thicker stuff.

 

[Dave 2000]

This is where my 93 idles after warmed up. It does climb to the halfway point as I add throttle. Believe I used 10w30 castrol on last oil change.

View attachment 2237616

Hi and thanks for posting. Unless you have calibrated that gauge (method in my long running thread) then it will not represent what is really happening in the engine. It is fiddly but worth doing.

The temperature gauge is set by the factory to red centre but it is 'dumbed down', unless you have modded it again it is not a true reading, the members handle I have forgotten who put the mod up is again in my thread: Builds - My LC 80 thread.

Thanks again.

regards

Dave

 

[Dave 2000]

I had the same issue on my 96 and my 97 when I used the ‘fancy oil’ full synthetic, Mobile 1, etc.
.Also developed a couple oil leaks with those types of oil. When I went back to regular Dino (following advice of Tools and Inkpot) the pressure got normal.
nothing against those oil‘s, I run them in my Hondas and Chevys and Acuras and they are fine.
I have heard that oversees this same engine was spec’d with different oil, thicker, and that the US engines have the thinner oil recommendation for gas mileage/mpg/EPA considerations. Have not confirmed that. My motors run better with the thicker stuff.

I have always used a 10/40 dyno in my 80 and never had an issue, but always used 10 litres of 5/30 or 5/40 to flush between oil changes.

The label on my usual 10/40 has changed to something like 'synthetic blend', but further investigation shows the adjustable oil pressure switch had got water logged, I have now fitted the new switch and calibrated it. Still early days as use of the 80 has been limited due to the lockdown now in progress due to the Coronavirus.

I did clean the old switch out and retried it and it worked fine, but as the new one is here it can stay fitted.

Thanks for posting up.

regards

Dave

 

[flintknapper]

This is such a common post on 'MUD' (perceived low oil pressure at idle). I was sitting on the highway this morning (traffic was stopped) and while waiting...thought I'd take a couple of pics...just so folks won't worry.

My Land Cruiser has 315K miles on it. I have both the factory sending unit and gauge hooked up as well as a digital gauge and separate sending unit to monitor (and compare) my oil pressure readings.

IMO, as long as your engine isn't 'knocking' you've got plenty of oil pressure.....so don't fret about the position of the needle on the gauge. Oil VOLUME is quite another matter. Don't let your engine get too low on oil. But pressure. Put it out of your mind.

 

[dewme5]

Toyota/Lexus 1uz is 4psi at idle. Not sure what info that trivia reveals, except that sometimes Toyota designs it that way.

 

[flintknapper]

Toyota/Lexus 1uz is 4psi at idle. Not sure what info that trivia reveals, except that sometimes Toyota designs it that way.

4 psi 'minimum' actually, but yes.....alarmingly low I thought...first time I read that. But I've never actually seen mine below 15 psi.

 

[designdca]

My fairly new to me ‘97 has the issue described here…almost zero at idle when engine is warm. Reading this mostly put my mind at ease, but….my oil warning light has also started coming on intermittently. Sometimes for a few seconds, sometimes for a few minutes. Usually not until driving at least 10-15 miles our so, but I can’t figure out any particular pattern or situation that causes it to come on. Ideas? Concerns?

 

[flintknapper]

My fairly new to me ‘97 has the issue described here…almost zero at idle when engine is warm. Reading this mostly put my mind at ease, but….my oil warning light has also started coming on intermittently. Sometimes for a few seconds, sometimes for a few minutes. Usually not until driving at least 10-15 miles our so, but I can’t figure out any particular pattern or situation that causes it to come on. Ideas? Concerns?

Oil 'warning' light is the oil LEVEL and separate from low oil pressure (for which there is no light).

Use the engine oil Dip Stick to determine the true level of the engine oil. IF you require empirical evidence for sufficient engine oil 'pressure' then install a mechanical gauge to satisfy that worry.

The engine oil level sensor in the oil pan is known to become 'sticky' in some instances and can cause an intermittent dash light. On the other hand.....it may be working perfectly and you might be low on oil, so check the dipstick.

OIl LEVEL Sensor:

 

[designdca]

Oil 'warning' light is the oil LEVEL and separate from low oil pressure (for which there is no light).

Use the engine oil Dip Stick to determine the true level of the engine oil. IF you require empirical evidence for sufficient engine oil 'pressure' then install a mechanical gauge to satisfy that worry.

The engine oil level sensor in the oil pan is known to become 'sticky' in some instances and can cause an intermittent dash light. On the other hand.....it may be working perfectly and you might be low on oil, so check the dipstick.

OIl LEVEL Sensor:

View attachment 3620874

Thanks for that info. I do check the oil level regularly and make sure it is never low.

 

[IdahoDoug]

Designdca, If the vehicle's oil is unknown, change the oil and put in Shell Rotella T6 Syn 5-40 with a new filter. Wal Mart has an excellent price right now.