Please Help! Oil Pressure Almost At Zero!

[Ki_spirit]

Please help!

After driving my car tonight, I have come home to find my oil gauge reading almost zero at idle!

I was driving, stepping on the pedal quite generously and at mid range rpm, the oil pressure is just below the last mark on the gauge!

There appears to be no leaks, although the wastegate of my turbo seems to stutter slightly under full boost repetitively, while being heavy on the pedal.

When cold the gauge can read close to the 4kg/cm2 line but once when warmed up goes down very low!

Please help!! Anyone! I will be ever so greatful for any help!

[kuma j]

check your oil level. if its low put some in it. if its not low then im not sure. maybe someone else here can help.

but first thing would be to check your levels. good spot to start.

[msnismo]

Standard gauge????? Notorious for reading wrong

Get another/borrow (aftermarket) and check it again.... could be just a faulty gauge.....

[GeeTR]

Borrow / see mechanic for a mech o.pressure gauge & test as soon as possible to be safe imo.

As Anna's said, the sender / gauge are awful. Replace sender with a known good one, then purchase a new one if the stocker ends up being bad. If issue still exists, then its most likely your gauge.

Incidentally theres a second o.pressure sender that flash's a red LED on the stock gauge. It'll illuminate at very low pressures.

Edited May 13, 2008 by GeeTR

[blind_elk]

How old is the oil? What type is it (mineral / synth)? What grade?

When the oil gets hot, such as after spirited driving as you have done, it becomes "thinner", and can't hold the same pressure at idle.

Absolute pressure is not as important as consistent pressure.

[rb2240sx]

I say check it with a an actual oil pressure gauge. If its still low then change your oil to something heavier until you can find the cause. If I remember correctly, there is a bolt on the bottom side of the oil pump that houses the oil pressure relief valve and spring. You can pull the spring out, stretch it out a bit longer, and reistall. Of course, a clogged oil filter could also be the coulprit. Whens the last time you changed the oil/filter?

[nuclear_skyline]

IS the engine making any funny noises? No knocks or clacking???

Oil pressure can drop really quick, be just maybe OK when driving, but have bugger all pressure at idle when nasty things happen t your main bearings, like spinning them.... Been there done that...

[Silver_R34_GT-T]

my R34 is doing the same thing. i mentioned it ot hte mechanic when getting a service, he said it was all fine, got the brand new oil in it, and my guage reads teh same

guess mine is faulty

[nuclear_skyline]

you can pick up a half decent autometer guage for round 150.... or a cheap working one for under 50..... may not be nice, but certainly will give u peace of mind

[Ki_spirit]

Hi guys,

Thanks for all of your replies.

The gauge seems to operate okay, and I have found when starting cold the the pressure is halfway between 4 and 8 on startup - I will look into the sender.

My sump although is still half full and I can see no indications of leaks...

The engine is getting slightly louder though, like the injectors and it is only recently that this has started to occur.

I have no idea what oil is in it, because the previous owner put it in. I am guessing from what he said it would be geting near 3000kms- guessing mineral, no idea on grade ; but I am going to change the oil ASAP (will have to look up what is in the book for the spec I guess).

Any recommendations? 185 XXX km's on car.

Am going to flush the radiator and refill as well.

Thanks everyone (kuma j, msnismo, GeeTR, blind_elk, rb2240sx, nuclear_skyline, Silver_R34_GT-T) for all of your help

[Ki_spirit]

Oh, another thing guys. What should the pressure reading be at idle?

[blind_elk]

Depends on the oil and the condition of the engine.

My RB25DET sits around the '4' mark (? , 1st line up) when everything's good (ie correct oil level in sump) and engine up to operating temp. I'm using Mobil 1 15W50 in an engine rebuilt about 10k ago.

As I said earlier, it doesn't matter what the reading is so much as it's stable.

[Ki_spirit]

cheers.

[Bliksem]

First thing I'd do is change the oil, that is just good practice since you've only recently bought the car.

It's also possible that there could be a small amount of oil contamination which affects the viscocity of the oil ie: small amounts of petrol escaping past the piston rings and making its way into your oil.

Once you've changed the oil (which imo you should do regardless), and if the problem still persists - get another gauge to test the real pressure. As others have said the oil pressure sender is known to be faulty.

[nuclear_skyline]

Heres a gooden I learnt... When you drop the oil out, make sure the pan is clean before hand and let the oil run into it...

Dont let it sit for too long and run a magnet through the oil to check for metal in it... If your engines getting louder, and your oil pressure is dropping off, could be a bearing issue...

[Ki_spirit]

Thanks guys, I really appreciate all of the replies.

I am going to change the oil today.

Ill tell you how I go.

[Ki_spirit]

Well, changed the oil. Pressure appears to be a bit more stable. Changed the filter as well - along with the gearbox oil. Runs more smoothly now.

Thanks for all of your help everyone