Low oil pressure???

[R1cky]

Pretty much the above:sad: . Start her up from cold and the pressure rises rapidly to around 7/8bar yet once its warm pressure will drop to 3bar max under normal driving conditions (60-70mph) and 4bar when the pedal hits the metal. pull up after some spirited driving and it'll go as low as 1bar. This is a bit of a worry as i doubt its done 10k since i had the thing rebuilt. Any help/advice would be great

 

[stevepudney]

Does seem a little low :?

What oil has been used since the rebuild and what's in it now, and was the Nissan oil pressure sensor renewed with the rebuild.

 

[scottyd]

I dont know if this helps at all, but on cold my oil pressure stays at 4bar, and when warm sits at 3bar, it never goes above 4 bar even when i boost it, so i'm not sure if you have much of a problem other than your oil pressure dropping as low as 1bar.

Either that, or both of us have a problem:doh: :lol:

 

[stevepudney]

It's his "pull up after some spirited driving and it'll go as low as 1bar" I'm worried about.

Do bear in mind that the stock oil pressure sensor is crap especially if original (14 yrs old)

 

[R1cky]

current oil is castrol edge 10/50 and thats all i've ever used in it apart from some vavloline mineral oil for the 1st few hundred miles after the rebuild. would it be worth getting a new pressure sensor then?

 

[pulsarboby]

dont worry about it;-)
the pressure varies from car to car, and as steve has said, the oil pressure sensor isnt that accurate at the best of times!

its when the pressure does not rise when you pick up the revs that you have got a problem!
as long as the pressure builds under load, then thats fine:-D

ive seen cars that hold 4bar pressure at idle, and have done a big end:shock: including one which i recently took on a trackday!

 

[Odin]

Maybe fit an oil cooler if you haven't already, That should stop the pressure dropping to as low as 1 bar when you're ragging it.


Rob

 

[R1cky]

Got a 19 row cooler sitting in the garage (probably not much help there). just gotta get some proper lines sorted so i can front mount it. oil temp rarely goes much over 85ish so not too sure if a 19row will be overkill?

 

[stevepudney]

dont worry about it;-)
the pressure varies from car to car, and as steve has said, the oil pressure sensor isnt that accurate at the best of times!

its when the pressure does not rise when you pick up the revs that you have got a problem!
as long as the pressure builds under load, then thats fine:-D

ive seen cars that hold 4bar pressure at idle, and have done a big end:shock: including one which i recently took on a trackday!

Dito

 

[cmng]

7/8bar oil presure

that is high man

 

[paz]

Have you checked the sump pan for dents?

Paz

 

[youngsyp]

Got a 19 row cooler sitting in the garage (probably not much help there). just gotta get some proper lines sorted so i can front mount it. oil temp rarely goes much over 85ish so not too sure if a 19row will be overkill?

I'd say that 85 C is pretty low. Mine sits at about 80 ish when warm, at idle and I've seen 110 C at the height of summer when driving enthusiastically. Have you got an uprate radiator ?

If you are only getting those temps, an additional oil cooler would be detrimental as, you oil would struggle to stay warm enough !

Maybe both the oil pressure sensor and temp sensor have had it ?!

 

[Odin]

Maybe both the oil pressure sensor and temp sensor have had it ?!

I would say that it is moor likely that the sensors are faulty, Because their is no way you're getting 85c when it's being ragged, Even I see 90c + and I have the 19 row cooler and a 53mm koyo Rad.

It must be getting pretty hot to drop the oil pressure to one bar mate.


By the way I just bought all new water/oil temp sensors (x4) and they are not cheap coming in at £180+, But I want everything on my new engine to work properly ;-) .


Rob

 

[stevepudney]

7/8bar oil presure

that is high man

my pressure shoots round to 8 bar + when started from cold then when fully warm idles at a scratch under 4 bar but even when fully warmed and been ragged mine sits at 7-8 bar at around 5000 rpm upwards

I have a thermostatic mocal 24 row oil cooler (overkill I know) but his time of year my temps never get higher than 90 degrees even after a blast on the motorway, in the summer I might see 95 degree if I have really canned it. Oh, and I chucked the Nissan electrical oil temp sensor and gauge ages ago and now use a Mocal mechanical oil temp gauge which I feel is a little more trustworthy.

Steve

 

[Fast Guy]

Oil pressure should be more than 0.98bar (14psi) at idle
and 3.43-4.41bar(50-64psi) at 3200rpm

;-)

 

[R1cky]

thanks guys. kinda put my mind to rest a bit there. was starting to panic if i'm honest. well sod it been wanting some flash defi gauges for a while now. just gives me a half decent excuse to buy some hey