3SGTE oil pressure maybe low?

[TurboRA28]

Howdy all, well the 3s-gte is running along quite happily now. Just ironing out a few bugs at the moment.

One being, I think the oil pressure is a bit low.

The oil setup consists of a 6 litre sump, remote oil filter, rx7 big arse oil cooler (with internal thermostat). Brand new genuine toyota oil pump.

The oil pressure sender is in the head.

Now when its cold its up around 50 psi at cruise, but as it gets hot its around 28 - 30psi.

I've only ever had engines with the oil pressure sender down in the block and understand that when measuring it from the head the pressure is going to be lower?

Just wanted to check if the pressure was ok or not? The reading doesn't vary much between idle and cruise either, like its just over 20psi at idle, and 30 at cruise. My old 3T used to be more like 15psi at idle and 40 - 50 at cruise.

My only thoughts are something to do with the rx7 oil cooler? Or these figures taken from the head are normal?

Cheers
Joel

Cheers
Joel

[Celica RA45]

you will need to put it in the oil line going to the cooler, so the alloy adapter on the block and tap it on the line that going to cooler in there the oil pressure will be higher and more accurate as well ,just a side note the altezza 3sge have theres in the sump right next to the filter
also the altezza oil pump is higher in volume my pressure is in metric so on idle sits on 200 to 300 and at full load sits up to 650 to 700 depending on the days temperature as well ,and im not using a cooler std water to oil heat exchanger from factory

[-==L=a=N=c=E==-]

http://ugbox.net/~lance/GT4/Technica...re%20check.pdf

By the toyota BGB, anywhere from 36psi to 71psi at 3000rpm is considered normal.

Mine sits around 45psi at cruise (2900rpm).

But then again, it really does come down to where you have located your oil pressure gauge. I have mine teed in where the stock oil pressure switch is.

[510rob]

I don't know if this is of any use, but...

The 1997(model year?) - 2001, 5SFE oil pump (Part No: 15100-74030) is the "high volume oil pump" for a 3SGTE

3S-GTE Gerotor OD: 59.92 mm x Gerotor Depth: 13.92 mm
98+ 5SFE Gerotor OD: 59.92 mm x Gerotor Depth: 15.48 mm

Most guys shim the 5SFE pressure relieve valve with a 1.25 – 1.5 mm shim. The 1998+ 5SFE oil pumps have a threaded oil pressure relief stopper.

5SFE drive pulley has two less teeth when compared with the Gen2 3SG motors (I seem to remember it is 25 vs. 27, but the Gen3 3SG motors may already have the lesser number of teeth). Also, the Gen3 3SG uses a 177 tooth timing belt, but the Gen2 and earlier use a 178 tooth timing belt. (presumably the later belt's lower tooth count is to compensate for the smaller oil pump drive pulley on the later motors).

[thechuckster]

you will need to put it in the oil line going to the cooler, so the alloy adapter on the block and tap it on the line that going to cooler in there the oil pressure will be higher and more accurate as well ,just a side note the altezza 3sge have theres in the sump right next to the filter

Dont you want the oil pressure guage to measure after the filter & cooler so you know what pressure is being fed to the crank bearings and up to head?

You may get a pressure drop across the cooler (despite the large lines)? a leak in the cooler will show up the instant it occurs.

I'd suggest tapping into the return line from the cooler.

cheers,
Charles.

[TurboRA28]

Hi all, thanks for the info on this so far..

Just for a test I bypassed the oil cooler, and picked up another 15 - 20psi oil pressure!

Which seems to put the figures right on spec.

Not sure why there is such a large drop with the cooler though.

[TurboRA28]

Ahh spoke too soon.. Went for a run today and once the engine was up to temp the oil pressure dropped back down to 30psi at cruise. Thats with the cooler bypassed.

Sounds like I better be tapping a pressure guage into the return line from the cooler/filter and see what the pressure is there.

[oldcorollas]

what oil are you using?? thinner oil = lower pressure at normal/low rpm.

i think it's always best to measure oil pressure where it is being delivered, as that is the most important pressure.
if you have it in the head, it will tell you when you have lost pressure in your main bearings...

it would be of interest for you to tap gauges into post pump, post cooler, and head, and monitor them as oil warms up (see effect of thermostat as well) at least then you know what pressure drops you have... pressure drop should be more apparent at high rpm/load (more flow and more oil shedding)

[TurboRA28]

Does anyone know if you can puchase some inline adapter with a tapped hole for the pressure gauge that you could put in the pipe from the external oil cooler?

Or would you have to tap into the spin on adapter itself?

[TurboRA28]

For a test I removed the external oil filter setup, and just put a Z386 filter on the block. This seems to have made a noticable improvement. I went for a 20min drive last night and after it was all warmed up seemed at cruise oil pressure was around 40psi, and would increase with revs slightly.

Still not sure if this is good enough or not though.

[The Witzl]

Joel - what RPM are we talking about here? Oil pressure is mostly a function of engine RPM....

On my old 4A-GE 100kW - oil pressure was ~20-30psi at idle, then increased with RPM until it reached full pressure (around 70psi) at 2500-3000rpm.
This was with a pricol oil press gauge, stock (worn) smallport 4age, toyota oil filter.

Are you using a Toyota genuine oil filter? They seem to have much less hinderance on oil flow than most aftermarket ones...

40psi seems pretty low for full oil pressure!

[TurboRA28]

When I had the oil cooler and remote filter all plumbed up, oil pressure did not want to get much over 30psi when warmed up, regardless of the RPM (well to a degree, didn't want to rev the shit out of it).

Now i've taken all that off, it is a lot more RPM dependant, like at idle its just above 20psi, and at 3000rpm around 40psi. At 5000rpm it was getting closer to 50psi.

But it doesn't seem to increase that much based on RPM which is my concern.

But then having the oil pressure sender in the head I wondered if by the time the oil has gone through the bearings and turbo it might be normal to have lost some pressure?

The turbo is a -6an fitting from memory.. I wonder if that is supplying too much oil and taking pressure away from the system?

[TurboRA28]

I should mention when it is cold its around 70 - 80psi at cruise.

[ae86trueno]

Sounds like a worn oil pump to me or too thin oil,
It sucks to check the internal clearances of them, but if you need another 3SGTE pump to compare or to test i have one here.

Cheers
Ben.

[TurboRA28]

Hmm it was a brand spanking new pump from Toyota

That was another thought.. I'm just using some everyday castrol oil to run it in on. Maybe it doesn't like getting hot and just thins out too much.. As the pressure is there when its cold.