Oil pressure - 3SGTE in an ST185

[punkture]

Heres the maybe problem? fitted the oil pressure gauge, its a speco one if that makes any difference, mechanical, on idle at running temperature the pressure was as low as 15psi? but when revved it was avergae 45psi etc.. 60psi on cold. I know the turbo is fairly dead as it has roughly .5mm play vertically. not much axial play though, this dumps a fair amount of oil into the intake, would this cause low oil pressure? or a leaking valve cover gasket, which is also leaking?? on a st185 3sgte

[mattysshop]

it shouldn't cause low pressure..

what thickness oil are you running?? it is a little low compared to what i have seen my mates one do..

is the engine unopened?

[andrew_mx83]

i have a speco mechanical pressure gauge. on a couple of different motors now it has shown 0psi @ idle, even when i know there is pressure. as soon as you give it a couple hundred more rpm the pressure comes up.... no idea why but it has done it for years.

i have since purchased an electric one, will see if it makes a difference once i get the car running.

[punkture]

engine was rebuilt apparently 20k ago, blows white smoke at idle, compression was good. not sure of the thickness, im planning on dumping it and putting in magnatec and a new filter

[mattysshop]

yeh if there was something not put in the right way or not right it would have killed itself buy now..

a mate of mine has a fully built gen 2, forged rods, pistons, etc etc (from terryo @ road and track), i do the servicing on it and i use HPR30 in it

[jonathan yee]

yeh my VDO elec gauge shows only 0-5psi when it's completely warmed up. goes to about 20-30 when driving/accl and sits down around 10-15 when cruising.

[punkture]

My stepdad whos a mechanic said the oilpressure will drop as your journal bearings clearance increases, and that mine should be 25psi on idle but it seems to be a trend that its lower than that..unless all our engines are fcucked haha

whats the viscosity in it 15-30? i used to work at repco hahah. yeah i figured magnatect should be okay, i googled sum gen 1 and 2 oil pressures, some had down to 5..haha, others were 25psi, and the BGB says 35psi i think. is their another way to test the pump life?

[CELICASUPRA7M]

You need to find out the spec for the motor and then get a proper guage screwed in for a comparison.
7MGTE's only run i think 4.7psi hot idle so dont be too alarmed if the spec is that low, my speco gauge shows 5psi hot idle.

[MWP]

Magnatec is nothing special.
Youll find a lot of people on here recommend Penrite oils.
I use HPR15 in mine.

0.5mm vertical turbo bearing play is ok.
That wont cause oil leaking unless your seals are shot.

[NME308]

Hi there,
Oil at the pressure of 'available' at idle is no major issue in most engines. 45psi at normal cruising in itself would not be a worry to me, just keep an eye on it and make sure it is not getting lower over time. Hell back in the day we quickly learned NEVER fit an oil pressure gauge to a standard Holden 6cyl engine as they would show no pressure at idle and bugger all more at cruise...

Not knowing if you have any/many mods in the engine bay - does your pcv system/catch can indicate much crankcase blowby? I ask this as large amounts of blowby will quickly contaminate good oil and reduce its viscosity thus the oil pressure at the same time. As somewhat of a side note I hope your PCV system is in good working order and/or you have a free flowing catch can system anyhow.

White smoke at idle sounds like my latest SR20 turbo... Partially cos its old and partially cos my oil drain is NOT to recommendable specs I had to put a really really small restrictor in the oil feed line to stop the turbo smoking. Turbo's are like engines - available oil even at low psi is good!

Cheers,
Jason

[andrew_mx83]

oil pressure is dependant on the viscosity of the oil, the temperature of the oil (viscosity drops as temperature increases) and bearing clearance.

u can get an idea of the conditions of a motor's bearings by how much oil pressure it has and also how long it takes to warm up from cold.

[Talasas]

Sorry to hijack but I'm on the same sort of page at the moment, except I've checked and my bearing clearances (except for small ends) and they seem okay. Would a bad oil pump gasket cause low oil pressure? For example if it was gasket goo and perhaps had a gap somewhere would that cause pressure loss?

[punkture]

hey, talasas, id assume it would as it would be relieving the pressure the broken gasket was torqued to. NME: theres no catch can but MWP im 100% certain my turbo is hammered, it seems it likes to destroy my intake with oil now, more so, and the only on boost oil out the exhaust.. new turbo time for sure =). there was a massssive leak today i found, i think it was when i did the oil press sender unit, i didnt use thread tape. i have now, hoping it fixes it, it came from that side of the engine bay..what is the price of a fresh turbo rebuild/hiflow, i dont want a 300kw monster engine, i want a nice responsie 190 atw max engine at the end of the mods. i was thinking a gt28r, or highflowing the ct26??

[AdrianS]

For comparison (figures from Toyota BGB)

'88 mr2 (4AGE)
oil pressure : idle = 29 kPa+, 3,000 RPM = 245-490 kPa (warm engine)
4+ psi @ idle, 35.5-70 psi@ 3,000 RPM

Blacktop
oil pressure : idle = 59 kPa+, 3,000 RPM = 245-490 kPa (warm engine)
8+ psi @ idle, 35.5-70 psi@ 3,000 RPM

[mattysshop]

hey, talasas, id assume it would as it would be relieving the pressure the broken gasket was torqued to. NME: theres no catch can but MWP im 100% certain my turbo is hammered, it seems it likes to destroy my intake with oil now, more so, and the only on boost oil out the exhaust.. new turbo time for sure =). there was a massssive leak today i found, i think it was when i did the oil press sender unit, i didnt use thread tape. i have now, hoping it fixes it, it came from that side of the engine bay..what is the price of a fresh turbo rebuild/hiflow, i dont want a 300kw monster engine, i want a nice responsie 190 atw max engine at the end of the mods. i was thinking a gt28r, or highflowing the ct26??

the second part of your question with the turbo -

the GT28R will be responsive as hell.. especially if you get a good manifold with a merge collector made and not just use the cast peice of shit..

http://www.youtube.com/watch?v=1M7SPk-t0qo

you can get GT28R's insanley cheap nowdays.. this video above was before it was tuned, it made 252fwhp on 1 bar... the injectors are pressty much at their safe limit..

that turbo and manifold (all HPC'd) with dump pipe (tapered divorced wastegate) setup will be for sale soon as he wants to put a GT3071R on it.. the setup isn't that old either..