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Discussion Starter · #1 ·
Just noticed today on the way home that the oil pressure gauge was sitting around 2kgcm2 at about 40mph ( in traffic 5th gear ) and then rises up to about 4kgcm2 at about 60-70mph again 5th gear.

Does this sound about right? I dont know if i'm just being paranoid as its first time i seen it this low and assume it wouldnt be a good thing?

No leaks identified and when this sodding rain stops i'm going to check me levels.

Thanks
 

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Never take anything the std oil pressure gauge says as gospel. Best things is to buy yourself an aftermarket gauge and see what that says :)
 

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my oil pres averages at about 4 kg/cm2 right after a cold start. then as soon as the engine warms, it drops to about 2 kg. and at any speeds between that and 140 (done on closed track :) ) its at about 3... is that bad?

ive compression tested all cylinders and all are within parameters except number 4 cylinder, which sits at about 9%-10% difference from all the rest... which i was told 10% is the limit... so should i swap out the rings? as i got spares on standby but its too much of a pain to take my eng apart to do so if it wont doa thing
 

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Anything within 10% on compression is fine.

The thumb rule on oil pressure is 10psi per 1000rpm, when did you last do an oil change as it should be done every 3000 miles.
 

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my last oil change was... about 3000 miles ago...

and about that 10 psi per 1000 rpm... my pressure never rises above 3 kg/cm2 even at 7000 rpm at 130 mph
 

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so what would be the reason for it being so low?
 

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i'd put another gauage on there and check it.
 

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BigBoy
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On that link, what does it mean by Discharge pressure ? (says at idle, its 1.1)

U see, on my GTT, as of today, it is now sitting at 1.1 pressure compared to the normal 2 as before... checked my oil, seemed low (got Silk Pro S 10w50 in there), went to halfords, nearest thing i could get was MObil 1 15w50 1ltr (at £14 !), so i banged that in, intention was to buy oil at JAE from Opieoils, and get oil change right after.. am a bit worried now though that i have kind of mixed the oil, and that my pressure at idle is right down... (usually sat at 4kg when driving at motorway speeds)....

and i thought decent oil on a Std GTT could last around 5k miles rather
than 3k miles ?

As said, mine is sitting at 1.1 on idle..
 

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On that link, what does it mean by Discharge pressure ? (says at idle, its 1.1)
Oil pressure.

U see, on my GTT, as of today, it is now sitting at 1.1 pressure compared to the normal 2 as before
That doesn't sound too good I would do an oil & filter asap & see what happens.

Hotter air temps & overheating can drag your oil pressure down as well.

I thought decent oil on a Std GTT could last around 5k miles rather
than 3k miles ?
The page from the manual was for an R33 maybe your R34/Neo oil pressure is different ?
 

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BigBoy
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well, the bloke from Opie said with the oil i got, i can do 6k with it, having a std motor (apart from intake...)

Just ordered 10w50 now, delivered thurs, probably got 50 miles to cover before i can get an oil change.....
It totally pissed it down today, and its windy, but not cold, no idea if thats anything to do with it....

But going back to the top question, according to that attachment link a few posts up, discharge pressure at idle is 1.1 , and 3.5 when at around 2k rpm .
Well, that is exactly how the oil pressure is showing in my car..... (but before, it was 2.0kg at idle....)
so am totally confused ! :( :( :(
 

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Just for comparison mine when cold is about 6 and 2 when warm at idle. When I'm doing about 70 - 80 its at about 4.5.

The pressure is generated by the resistance to flow and not actually by the pump. As the revs increase the pump delivers oil at a higher flow rate through the same holes hence the pressure increase. If the pressure is less at the same revs than before, this could be a early warning that the pump is worn and inefficent due to slippage.

Advise from a hydraulic engineer rather than a mechanic.
 
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