OIL PRESSURE! What is it??

[skylineakt]

Hi guys

This might be a really stupid question, but I got to find out as my oil pressure is playing up.

I recently went on a pretty hard cruise, and the day after my oil pressure was really low. Like in between 0 and 2 (idling). Normally it will be at around 2 and 4 when cruising.

It went away for a few day and now it is back again.

I'm pretty sure it is not the gauge being faulty, cause if it is the car will feel normal even if the gauge indicate low. But I can actually feel something different when it is low! In fact it idles even smoother.

I changed my oil before the cruise and I rechecked its level and it is fine.

I don't even know really what does the oil pressure do?! I assuming that its measure the pressure of the oil inside the engine??!! So what can cause the oil pressure to be so low?? I have been using 5-30w oil for a while now and all the other time it was fine, I also change my oil every 5000 ks.

Is there something I can check to find out what is wrong. My car is not due for a service in another 5000ks and I don't really have the time to take it in to the workshop yet.

So any help or advice from here would be great.

Cheers

Skylineakt

[wrxhoon]

i posted the oil pressure specs on another post have a look there for ur car . remember that pressure will be higher when cold ( oil is thicker) and if u use thin oil it will be lower .that will explain the reson ur pressure was lower after driving hard oil temp would be very high .at idle speed between 0-2 is normal when hot .around 4 is normal just cruising along at 2-3000 rpm ( hot oil ) but remember the oil takes a lot longer to get hot ( normal temp ) than the coolant .coolant temp goes to normal after 3-5 minutes oil may take 30 min .

[skylineakt]

Thanks for the info wrxhoon.

I'll try to find the post.

Cheers

[Busky2k]

The pressure was low because ur oil was very hot and thus thinned out ----> lower pressure. I would suggest using xW-40 oil if you drive your car hard!! If your pressure drops very low, just keep the revs up to keep the pressure going...

[wrxhoon]

u dont need high pressure to protect u r engine u need volume . at iddle speed 7.5 psi is o k thats like .6 on your gauge

[Ronin 09]

the R33 factory senders/gauges are notoriously inaccurate. My sender cracks it after warming up and will only read about 3 on in the dash. I have a Greddy oil pressure gauge, and it is much more accurate - reads about 5-6 (kgcm-2) when going for it, 1.5 on idle. If you're worried get an aftermarket gauge.

[Skyhigh]

If you changed the Viscosity (spelling?) of the oil,

eg from a 5W/50 to a (which is thin) to say a 15W/50 (Thicker)

then the pump will not pump as fast, therefor less pressure.

Stephen

[wrxhoon]

thicker oil will give u more pressure cause u have more resistance stephen . as i said before pressure will vary depending how hot the oil is and oil takes a long time to get hot unlike coolant that gets hot quick .if u have an oil temp gauge u will notice that .

normal driving after about 1/2 hour it gets to about 110 degrees, if u race the car it will get up to 150 degrees .