Oil pressure max

wotugonado · July 26, 2017, 21:59

Can anyone tell me at what pressure (in bar)oil pressure is likely to start causing an issue ?

1979scotte · July 27, 2017, 07:03

In bar no.
When I had oil pressure rigged up on my 1zz it would be very high from cold say 90psi.
During normal operation it would be something like 20psi at idle and 60psi at WOT.
Maybe takes as long as 20 mins to settle down far far longer than say the water take to get up to temp.
Pretty sure there is a thread somewhere in which Carolyn and myself discuss this.

Carolyn · July 27, 2017, 08:44

By 'issue', do you mean putting too much strain on the pump? Also, it would depend on the root of high pressure, i.e. Thicker oil, tighter bearing clearances, or sludge in galleries, or?

I would be concerned if (once it's thoroughly warm) it idles above 30 psi or cruises above 80 psi, though I don't really know the limits to the standard pump.

theredone · July 27, 2017, 10:26

Quote from: "Carolyn".......I would be concerned if (once it's thoroughly warm) it idles above 30 psi or cruises above 80 psi, though I don't really know the limits to the standard pump.

the above figures are what I get in my 2004 yaris. different engine, I know, but same era and probably built to the same tolerances as 1zz. when cold the oil pressure goes over 90psi

wotugonado · July 27, 2017, 19:40

I have no specific issue (I hope), I do have a faulty gauge which I'm finally getting round to swapping. The new one has a built in programmable warning sensor and I just wondered what would be a reasonable limit to set it at....
I'm turbo'd
Run Fuchs oil 5w-40

if the pump dies then would the engine be fubar ? If so this would be where I'd like to set my warning

Carolyn · July 27, 2017, 19:55

Pump failure would be a total fubar. It's hard to see the value of the warning.... but at the low end <10 psi at the upper end >115 psi would be my best guess, but you might well hit that with 5W40 and some revs when stone cold.
It's all about letting the oil warm up properly before you put pedal down hard.
I do prefer analogue to digital in this application. When the pressure is down to around 20 psi at idle, the oil is up to temp.
Having said all that, these pumps are very reliable.

wotugonado · July 27, 2017, 20:09

Thanks for that. Do you know what pump we have so I can do some searching for info ?
I totally agree about letting it warm up, i think an oil pressure gauge should be fitted as standard, before my old one packed up I found it an essential bit of kit to get the engine warm before giving it some abuse.

1979scotte · July 28, 2017, 07:49

Quote from: "Carolyn"Pump failure would be a total fubar. It's hard to see the value of the warning.... but at the low end <10 psi at the upper end >115 psi would be my best guess, but you might well hit that with 5W40 and some revs when stone cold.
It's all about letting the oil warm up properly before you put pedal down hard.
I do prefer analogue to digital in this application. When the pressure is down to around 20 psi at idle, the oil is up to temp.
Having said all that, these pumps are very reliable.

Agree with your figured above Carolyn.
My car would be at 90psi just pootling along from cold would imagine 115psi would be hit easily with a bit of WOT.
That's why you need to give it a good long while to warm up.

Carolyn · July 28, 2017, 09:54

The pump is unique to the 1ZZ. It is sited around the front end of the crankshaft, not in the sump.
I've done a bit of Googling on oil pumps. It seems that no-one does a high performance oil pump for the 1ZZ. Such an item is available for the 2ZZ, but they are not interchangeable.
So the best one could do, for maximum pump performance, is install a new OEM pump.