Oil Presure Question

[BNR]

Hey

When driving my oil presure gauge sometimes drops all the way down to sitting just about the 0. When i start the car it goes up to 4 but when i drive it mainly sits on the line below the 4. Any ideas why it would be doing this ? Car hasent lost any power. Car is a R32 GTR

Thanks

Edited August 28, 2005 by BNR

[Cubes]

It may be the sender.

Mine does this 'occasionally', the little ol rb20 did this as does the rb30. My sender is dicky and appears to play up 'occasionally' when it gets hot. Completely random, then all of a sudden its ok again.

It may be the oil your running?

My oil pressure when cold is well over the 8. Idle is inbetween the first and second line. Cruise is some where above 4 and above 3500-4000rpm is up around 7.

I'm using an rb25det pump.

[MerlinTheHapyPig]

i have same problem, i just assumed the sender was f**ked because a lot of people report this problem, (and my engine hasn't died or anything!)

[Abo Bob]

Even the R34 sender is crappy. It's the one thing Nissan didn't seem to figure out.

[justin911]

if the sender is stuffed, does that mean if u put an aftermarket guage on you will still see the same results as the stock guage ??....

just out of interest.. where abouts is the sender... or how would u go about hooking up and aftermarket one ?

Even the R34 sender is crappy. It's the one thing Nissan didn't seem to figure out.

[Craved]

if the sender is stuffed, does that mean if u put an aftermarket guage on you will still see the same results as the stock guage ??....

just out of interest.. where abouts is the sender... or how would u go about hooking up and aftermarket one ?

the sender is screwed into the block about 1.5 inches the rear of the engine from the oil filter.

you would replace or use a T piece to screw in both senders. ( i have a thing about dash guages still working even though i have aftermarket)

in the pic below the sender is screwed in where the line going from bottom left to top right of the block is.

Edited April 7, 2006 by Craved

[justin911]

cool thanks heaps for that

if the sender is broken though.. wouldnt it send incorrect results to the aftermarket guage still ???

[Craved]

cool thanks heaps for that

if the sender is broken though.. wouldnt it send incorrect results to the aftermarket guage still ???

aftermarket guages come with their own sender ... thats why you use a T piece so they are both hooked up and working (even if stock one is wrong)

[MerlinTheHapyPig]

you'll also find that most oil filter relocation kits (or oil cooler kits) have a sandwich plate which goes between the oil filter and the mount, most people tap aftermarket oil temp/oil pressure gauges in here.

[frankxinyu]

yeah, i would say the sendor unit a swell. mine is sitting just above 0 as well when it idles hot. then pulled the sendor unit apart, it was actually leaking oil through it. then put on a mechanical oil pressure gauge, and the reading is on 2.5 bar hot idling, which is fine.

apparently according to Nissan, when the rpm is at 950, the oil pressure should be on 1.5 bar hot, which proved mine was fine.

[xr8eater]

somthing to chew on

when you fill your engine up with oil and you fill it to the top of the full line on the dip stick the oil presure should be 3.9-4.0 cold 1.9-2.5 warm.

but if you fill the engine to 2mm below the full mark on the dip stick the oil presure cold is 6.8-8.0 and 2.5- 4.0 warm the big question is what is better for the engine.

does it work like this lower presure lower oil flow warmer engine? or higher oil presure higher flow warmer engine?

i am lost at what to do i will leave it to the brains trust

SK will probably know what to do

[LatinR33]

another case of dodgey sender unit. Explains why alot of skyline owners buy aftermarket gauges.

[xr8eater]

i wouldent say dodgey sender unit just a differnce in volume of oil

btw my oil is 5-50 full synth

[Godzilla32]

When the oil is cold its thicker = more pressure, as it warms up you get thinner oil and slightly lower pressure (at low revs anyway)

[xr8eater]

verry true

but would it be better to run the engine with high presure or low presure?

[Godzilla32]

Low pressure is the killer of engines. With not enough oil pressure between bearing surfaces etc they begin to touch and wear on each other.

[xr8eater]

awsome some one with a clear answer

[Godzilla32]

The oil when under pressure creates a very thin film of oil between the two surfaces keeping them (in a way) insulated from each other.

Thats what i think is called pressure lubrication where as in say a gearbox they utilise a splash lubrication.