Low oil pressure in my 3B

[BillyGHusk]

So now that I have a mechanical oil pressure gauge I see that I have low oil pressure.

From the manual it says.

Idle 4.3 psi
3000 rpm 36-85 psi

I am no where near that.

Idle is at best 3 when warm and at 3000 rpm I am not making 20.
Running 10w-40 Amsoil syn.

Other than low oil levels what can is low oil pressure a symptom of?
From what I was told by the PO the engine should have around 80000 miles.

Thanks for any thoughts.

Tim

 

[canucksafari]

I would be guessing a bad oil pump.

 

[BillyGHusk]

yea, I guess I wasn't thinking about it enough huh?

So that begs the questions how hard is it to replace the oil pump in a 3B?

Well and more important are the available?

Thanks again,

Tim

 

[canucksafari]

That I can't say. Probably isn't too hard. I am sure that the vendors here on MUD can get you a used, rebuilt or new pump. EBI, G&S, Cruiser Dan are just a few that come to mind.

 

[exmodlad]

yea, I guess I wasn't thinking about it enough huh?

So that begs the questions how hard is it to replace the oil pump in a 3B?

Well and more important are the available?

Thanks again,

Tim

The pump is in the timing gear housing ...

see pictures with the oil pump installed..yup its for sale

Best Regards

Gord

 

[BillyGHusk]

I must say, after reading through my electronic manual, this is out of my ability level at this point and time. I am also trying to get a house ready to sell and move in 1 1/2 months.

Is this(the oil pump going out) the only thing that could be causing this. I was a quart low, but that really didn't help that much.

Thanks,
Tim

 

[roscoFJ73]

I must say, after reading through my electronic manual, this is out of my ability level at this point and time. I am also trying to get a house ready to sell and move in 1 1/2 months.

Is this(the oil pump going out) the only thing that could be causing this. I was a quart low, but that really didn't help that much.

Thanks,
Tim

The most common cause is old oil that has lost its viscosity. My old 3F would jump up 15 psi with an oil change.
In fact,I could tell when its due for a change by the oil pressure.
Apart from the oil pump,the other major cause is worn main bearings.

Fixes other than replacing parts ,are thicker oil.

However IMO it could go for a long long long time with 20 psi. As long as the oil is getting to the top,thats all it needs.

See page LU2 of the 3B manual for trouble shooting

You could use 20-50 which is what is required in warm climates

 

[BillyGHusk]

The most common cause is old oil that has lost its viscosity. My old 3F would jump up 15 psi with an oil change.
In fact,I could tell when its due for a change by the oil pressure.
Apart from the oil pump,the other major cause is worn main bearings.

Fixes other than replacing parts ,are thicker oil.

However IMO it could go for a long long long time with 20 psi. As long as the oil is getting to the top,thats all it needs.

See page LU2 of the 3B manual for trouble shooting

You could use 20-50 which is what is required in warm climates

All good information...thanks a ton....I was starting to wet myself thinking about getting the pump changed in the next month and a half. As far as getting oil to the top does this count? It is where my Amsoil bypass filter dumps. I expect not, I would expect you are talking about the piston skirts.

 

[lostmarbles]

Where does your Amsoil bypass filter get its oil pressure/flow from Tim?

I was just wondering whether the Amsoil filter could somehow be responsible for your low oil pressure problem.

I don't know much about them but I assume it should get its supply of oil from the bypass valve located on your stock oil filter housing.

And doesn't this bypass valve open only when your oil pressure exceeds specification (or am I wrong there)? If so - shouldn't your Amsoil filter be getting starved of oil (for it to filter) if your oil pressure is below spec?



PS. I'm at work at the moment so I can't look at my manual to check the bypass circuitry. So I don't really know much about what I'm talking about. (So what's new - I hear you say.)

 

[bull]

Billy I have a snap oil mechanical oil pressure gauge. We could hook it up to a where your sender goes and get a legit reading.

There is a Seattlecruiserheads meeting Tuesday in Queen Anne we could do it then..

 

[BillyGHusk]

Where does your Amsoil bypass filter get its oil pressure/flow from Tim?

I was just wondering whether the Amsoil filter could somehow be responsible for your low oil pressure problem.

I don't know much about them but I assume it should get its supply of oil from the bypass valve located on your stock oil filter housing.

And doesn't this bypass valve open only when your oil pressure exceeds specification (or am I wrong there)? If so - shouldn't your Amsoil filter be getting starved of oil (for it to filter) if your oil pressure is below spec?

The Amsoil filter and the gauge get their oil here....
This is tapped into the oil galley. The gauge is the one going straight out and the Amsoil filter is the one making the right 90.

 

[BillyGHusk]

Billy I have a snap oil mechanical oil pressure gauge. We could hook it up to a where your sender goes and get a legit reading.

There is a Seattlecruiserheads meeting Tuesday in Queen Anne we could do it then..

I would love that but my wife is out of town till Thursday this week....and that leaves me at home with the little one.

Thanks for the offer.

I think I will change the oil and see what happens there before I start ordering a new filter, sent Cdan a pm...

Thanks again for all the input guys!!

Tim

 

[lostmarbles]

The Amsoil filter and the gauge get their oil here....
This is tapped into the oil galley. The gauge is the one going straight out and the Amsoil filter is the one making the right 90.

So that would mean - plugging/closing the line to your Amsoil filter should raise the pressure shown on your gauge (and supplied to your bearings etc) - because presently some of your oil pressure is being "released/lost" via the Amsoil filter?

Why don't you try doing this and see if your oil pressure returns to "within spec" Tim?



PS. I thought the Amsoil filter was supposed to be connected into the bypass circuit so that it filters oil ONLY when the engine is revving (at which point the relief valve has opened to release surplus pressure/flow). But I admit I have never "read up" on these things. In the bypass circuit - it wouldn't lower your oil pressure.

PPS. And I'm assuming - that the oil pressure relief valve on our cruisers is there to "prevent excessive oil pressure" rather than to "bypass a blocked/clogged oil filter". (And I'm not sure this assumption is valid because I'm at work and don't have access to my workshop manual.)

 

[roscoFJ73]

All good information...thanks a ton....I was starting to wet myself thinking about getting the pump changed in the next month and a half. As far as getting oil to the top does this count? It is where my Amsoil bypass filter dumps. I expect not, I would expect you are talking about the piston skirts.

I didnt know you had the amsoil bypass filter. The oil comes into the head via the tappets in the rocker cover.
You can see it on some engines when you take the oil filler cap off.
The pistons get their lubrication from the oil squirters inside the block.

 

[Otterav]

Hello,
I agree, the amsoil thingy is your problem! s***can that thing, you are taking pressurized oil from the galley into a filter that has very little resistance and dumping it back into the pan, via the drain for the rockerbox. If you do not get rid of that, you will be replacing your main bearings, asap. As soon as you plug that huge hole in your oil system, your pressure will jump 2-3X. If you wanna take care of your engine? cut the oil change interval in 1/2, and change your filter at the midway point in the oil change cycle. Synthetic oil is great if you need it, unless you are turbo charging your motor you most likely don't need it. Use good quality diesel rated oil and change liberally. The extended oil change intervals of synthetic doesn't remove the soot(carbon) from the oil, thats why its black. I hope you haven't phucked the bearings!
Good luck
eric
P.S. from the pics shown, the filter is being fed from the unused galley plug behind the alternator, not the bypass pressure oil. I am amazed that your engine still runs, I hope your low pressure EDIC system is still operational.

P.S.S. Do not drive any more than you have to until you get that filter tee plugged with a plug, A.S.A.P.

 

[BillyGHusk]

So that would mean - plugging/closing the line to your Amsoil filter should raise the pressure shown on your gauge (and supplied to your bearings etc) - because presently some of your oil pressure is being "released/lost" via the Amsoil filter?

Why don't you try doing this and see if your oil pressure returns to "within spec" Tim?

Hello,
I agree, the amsoil thingy is your problem! s***can that thing, you are taking pressurized oil from the galley into a filter that has very little resistance and dumping it back into the pan, via the drain for the rockerbox. If you do not get rid of that, you will be replacing your main bearings, asap. As soon as you plug that huge hole in your oil system, your pressure will jump 2-3X.

P.S. from the pics shown, the filter is being fed from the unused galley plug behind the alternator,

Ok, so from now on please refer to me as "the village IDIOT!"
I pulled the feed to the Amsoil filter off and indeed my cruising pressure is about double and my idle is about 3 times higher.

Thank you all very much!!!

So as I have this filter and all where is the "bypass circuit" and would I be able to tie in there with the filter?

Tim....er....idiot

 

[BillyGHusk]

so from my electronic manual I find the relief valve at the back of the oil filter assembly....can I tie in at the relief valve with the supply for the bypass filter with out any issues?

thanks again,

Tim

 

[lostmarbles]

I'm spraypainting again this morning (which is an unusually warm winter's day so I can't afford to miss it) Tim so I don't have a lot of time right now. But I have been studying this diagram from my manual and it is not much help to me:



And I always thought Toyota had mislabelled item 4 in this drawing by calling it "OIL COOLER bypass valve":



(These linedrawings are from my B engine manual and I'm assuming the 3B is similar.)

At the moment, IF I was going to fit an Amsoil filter, I think I'd probably fit it into the oil-supply line (smaller one) that goes to my vacuum pump. I understand that this "dumps into the crankcase" though so you wouldn't get the extra oil "up top" that you now have. (One advantage of this is that the pipework might look tidier though - if the filter was to be mounted near the vacuum pump.)

(I'd probably like to double-check that the oil dumps straight into the crankcase before doing it though.)

But I'm sure there are people out there who know the 3B oil circuitry inside out and can explain it to us properly. We need to know exactly what the relief valve (or relief valves - plural - if there are two) do in the circuit. In my manual - toyota lists just one relief valve associated with the cartridge-type filter and labels this as an "oil cooler bypass valve". (Why would you want to bypass the oil cooler with some sort of relief valve?) And it lists two associated with the paper-element filter which it lists as "oil filter bypass" and "oil cooler bypass". ----- I'm baffled.

After thinking about it - It is probably not so baffling. If the oil is cold, it's viscosity tends to be higher (and hence the oil PRESSURE is higher). Pressumably the oil cooler bypass valve detects this and forces most of the oil direct to the bearings etc. But when the oil starts getting too hot its viscosity and pressure fall making the relief valve divert oil though the oil cooler to correct the situation. ....... And a paper element has more tendency to collapse-when-clogged and contaminate everything - so the engineers fitted an oil-filter-bypass valve to protect from such an event. (Supplying unfiltered oil to the bearings is a "lesser evil" than bursting the element.) ....... So Toyota never envisaged "excessive oil pressure per say" as being a problem and so never took any action to prevent it.

So from what I see - There doesn't appear to be any relief valve used to "limit maximum oil pressure" (which is what I think we would want ideally for "tapping into the outlet of" for your Amsoil filter).

Any others willing to give their opinion? (This is an interesting topic for me.)

 

[Otterav]

Hello,
Glad you found out what your problem was. The Amsoil folks make the same assetion over and over again and it's really voodoo mechanics. Uber filtration is a waste, particles smaller than the smallest oil film clearance is wasted filtration. I will reiterate changing the oil more frequently and filters at the 1/2 way point will do more for your engine than the Amsoil synthetic/filter setup. I had a SAE paper on the oil filtration particulate size on the desktop but chucked it while doing a reboot. Its out there, look. In the meantime change the oil regularly and you will get maximum life from the engine. The Japanese engineers got it right, enjoy the product!
eric

 

[brownbear]

There is no need on a 20 yr old engine to run the amsoil.... glad you pulled it.

Also you should be running 15w40 in that engine for the summer months. They are older engines and need the thicker oil. I'm running 15w40 in Northern BC. Colder average than you are.

Also don't faithfully believe a gauge unless you absolute on the calibration. Most gauges are for reference and should not be the determining factor to which your engine is toast or not. Keep in mind they are not accurate. Brand new aircraft pressure gauges still need to be calibrated by a master gauge that is verified each year. No way a cheap automotive gauge is perfect.