(Slightly) Low Oil Pressure on a 3B

[Diescipel]

I may be a paranoid new owner, but the oil pressure on my new-to-me 83 BJ42 (now successfully registered in Cali!) seems a little low. It is below the second hash mark from the left (i.e. there's the hash mark for the "L", then the next one to the right of it) even when the rpms are high. I have a receipt for an oil change in Oct. with 15W-40 oil, which is pretty heavy but maybe too light for this engine down here where the ambient temps are maybe in the 30s F overnight but usually in the 50s F during the day? Here's my plan of attack:

Get an oil pressure gauge and measure pressure, compare to factory manual.
Depending on the results of the oil pressure test:

If pressure good:
Clean contacts at oil pressure sender
New oil pressure sender

If pressure low from gauge test:
Heavier weight oil (20W-50)
New relief valves (wishful thinking)
New oil pump (mommy )

What ya think?

Thanks,
B

BTW I believe driving the BJ42 lowers the blood pressure. It is just so smooth and groovy and slow and solid and substantial. One just gets this feeling that everything else can wait.

 

[tlcruiserman]

something to check...

Hello,

Silly question, but you have oil for Diesel engines in the motor right? In any case this is in a BJ42? (nice I have an 84' BJ42 also titled and registered in California) I have found that the dash gauges on 40's and 70's are not so great, if the oil pressure was dangerously low the engine would shut off (there is a low pressure sensor as well.

I run Rotella 15w 40 in all my 3B's.

Not sure if that helps but something to check into is aftermarket pressure gauge.

Cheers,

Michael

 

[Stone]

I don't know if it's exactly the same issue with a 3B, but my 13BT as well as all of the other 13BTs that I've seen are notorious for reading on the low side for oil pressure (according to the dash gauge). But in every case, when an accurate pressure gauge is places on the sender, there's been plenty of oil pressure. So maybe check the actual oil pressure first and get a feel for how your dash gauge is reading...you're probably fine.

15W40 oil is what most people run year round. A good quality oil like Rotella, or Delo should provide all the protection that you need for the 3B.

Congrats on the registration!

 

[crushers]

if in doubt or worried always do a mech test, better yet install the guage and be done with it.
the toyota guages are for guesstiments only.
cheers

 

[cruiser_guy]

I wouldn't run a heavier oil than the 15w-40 unless I was going on a long trip where the truck would be started once a day and then run constantly. Make sure the oil is a "C" rated oil (I haven't seen a 15w-40 that is not "C" rated. Make sure the wire from the low oil pressure switch is connected (it's on the passenger side of the engine). If it's not connected the low oil pressure cutoff doesn't work. It works by grounding out the wire on low oil pressure.

 

[lumpy70]

I totally agree with these wise folks. After doing my rebuild, on initial startup I was reading no oil pressure with with the factory gauge....on my new engine!!!!!!!!

Freaking out only a little, I went and installed a permanent mech oil pressure gauge. Everything is fine now.

I believe the FSM calls for as low as 5 lbs at warm idle and 20 lbs at warm high speed. Anything over that is gravy (I'm getting 25 lbs and 55 lbs).


Craig.

 

[Diescipel]

Thanks folks. All seems well then. Maybe I'll check it with an oil pressure gauge but sounds unnecessary, especially since there's an oil pressure shut off (yes, the wires all look properly connected, as I was hunting around down there to familiarize myself with oil pressure mechanicals). Yep, oil is for diesels: Castrol RX Super (API CI-4) for diesels. I'll look for the Rotella on the next oil change.

Do you recommend 15W-40 all round for the temperate climate of coastal Northern California?


B

 

[NStimac]

oil pressure

Just to add for completeness

Factory spec is

4.3+ psi at idle

36-85 psi @ 3000rpm

 

[Mick]

I don't know if it's exactly the same issue with a 3B, but my 13BT as well as all of the other 13BTs that I've seen are notorious for reading on the low side for oil pressure (according to the dash gauge). But in every case, when an accurate pressure gauge is places on the sender, there's been plenty of oil pressure. So maybe check the actual oil pressure first and get a feel for how your dash gauge is reading...you're probably fine.

This is like music to my ears.

 

[waaz]

Hello
You may want to check your low oil pressure shut down. You will need an ohm meter.
With the engine off pull the wire off the pressure switch. It is located on the passenger side of the engine slightly above and forward of the oil pressure sending unit. With the engine not running you should have continuity or a short. With the engine running you should have an open or no meter deflection. Now with engine running short out the terminal of the wire to ground and the engine should stop. If it does not, then you have a broken wire or a bad connection at the EDIC.
Hope that helps
waaz

 

[Stone]

Thanks for the tip, WAAZ!