Oil Pressure Really High When Cold

[PHaT MR30]

when starting from cold my oil pressure (greddy EL gauge) gets insanely high just at idle, the gauge itself goes to 10 kg/cm2 and it goes beyond 9 on cold, and if you touch the throttle it will continue (and red led will illuminate).

It runs pretty crap while cold and is un-drivable like this (bit of smoke if revved when cold). Once it gets up to normal operating temperature the pressure drops to about 4-2 at idle and will go up to 6 when revved a bit.

I put fresh oil in recently (Motul Turbolite) and its only been driven probably 20 km's since.

My main concern is its got a smaller oil filter (random SR20 filter i had spare) on it than standard as the normal one didn't fit (RB conversion into S13, doesn't clear the engine mount). I wouldn't have thought this would be a problem, but im no expert either.

Please help, this is stressing me out to the max! I just want to be able to drive the car not watch the pressure gauge!

Cheers

Tim,

[paulr33]

10kgcm2 is too high

when engine is cold i would expect around 5-6kgcm2 at idle until it warms up

do you have like a mega sump or very low oil volume

whats the state of the oil pump / and oil system?

how much oil is in the engine?

[PHaT MR30]

10kgcm2 is too high

when engine is cold i would expect around 5-6kgcm2 at idle until it warms up

do you have like a mega sump or very low oil volume

whats the state of the oil pump / and oil system?

how much oil is in the engine?

Hi Paul.

Its a standard sump, i have put about 4.5 litres maybe a bit more in it. Oil pump/system is unknown as I bought the bottom end already built and just had my head bolted on.

I just keep thinking maybe the oil filter??? Im pretty sure the oil filter is a z442 when it should have a z145a.

Or is it more likely the oil pressure reg is stuck?

[Cjmartz2k]

What weight oil do you run? If it's something like 20W-50 and it's cold out, it can get pretty high. What's the bypass spring pressure on a stock pump?

[PHaT MR30]

Nah its Motul Turbolite which is 10W40 and i know of numerous people who have used this with no issues for many years in RB's.

Im putting it down to a couple of things:

Oil Filter

Oil Pump (could be an N1?)

Pressure Regulator?

Something else....

[Duncan]

Hey Tim I run a z224 on the race car because z145 didn't fit with the sandwich plate. It might have some osrt of blockage but the part# is fine.

[Swiper the Fox]

Hey Tim I run a z224 on the race car because z145 didn't fit with the sandwich plate. It might have some osrt of blockage but the part# is fine.

do you do this all the time? is this the tiny filter that cannot flow large volumes at high rev's starving your engines of oil and trashing your bearings?

[PHaT MR30]

Well im borrowing a mechanical gauge on the weekend to check (old man isn't convinced and thinks maybe the gauge is playing up), but when I got it home from an AIS check at idle it was sitting at 1 kg/cm2 (15psi) which is about normal... weird.

anyway its just not right still and im not risking doing any damage, but seriously CBF taking the engine out AGAIN

[Guilt-Toy]

get a second opinion... what i am trying to say is try another gauge!

[Duncan]

interesting question Paul. I've been running it for years on the race car and only had 1 motor fail with oil problems. And I am more tempted to blame that on the crack in the block's oil feed than the size of filter.

The really inconsistent readings suggests the sender, that is what we saw on both we have seen fail. but its still not worth taking the chance

[PHaT MR30]

Hmm well i put an industrial gauge on it over the weekend, when cold its sitting around 80psi, but once warm its sitting at about 15-20psi.

Im going to see an oil specialist and see if changing grades might help just for cold starts (cold morning today and it was blowing smoke a fair bit), but once warm wasn't.

Im also thinking maybe its rich at cold start and idle since ive changed a few things in my fuel system (rewired fuel pump etc), so once i change oil's im gonna get the tune looked at, as on boost its fine.

[Strik3r]

80psi (5.5 bar) is fine for cold oil pressure

[PM-R33]

Yeah seems fine to me. On cold start mine sits at about 70-80psi on normal driving, if i have to give it a bit when cold it hits up to 100psi. After a couple of minutes it goes back to normal around 50-60psi. Using Chrono 10W40.

[2rismo]

15psi is lower than i would have thought for an RB at idle to be honest.

[Silver_GT]

15psi is lower than i would have thought for an RB at idle to be honest.

depends where your idle is set, if its set at factory 650rpm (which most cars dont seem to be anymore) then oil pressure can be down around 15, if it idling around 1000rpm it will be up around 25-30 (on my r34 this holds true anyway, im assuming it would be the same in all rb's)

[Ultimategtr]

I just ran 3 oils thru my engine over the weekend and a flush(due to some reason) and currently have Castrol magnatec 10w40.

On a cold start the factory oil pressure sits a few mm over the 4 bar mark

On a warm idle its around 2 or under. As far as i know - if your oil pressure drops BELOW 5-7psi - THEN you have a problem, anything over that is fine.

Phat mr 30 - Do you still have the factory oil pressure gauge? If so - whats that sitting at?

[PM-R33]

15psi on idle

I don't think i've ever seen my oil pressure go below 40psi.....

[Wacky Dee]

whats 40psi in kg/cm2 ?

[woolls]

whats 40psi in kg/cm2 ?

2.81

[Jet 20]

with my rb20det when cold it idles at about 55 psi and when cold driving sits at about 75 to 80 psi.

when hot it idles at 900rpm and 25 psi and drives at about 55 psi.

thats with penrite sin 40 (i think thats what its called)