Jump to content
SAU Community

Recommended Posts

Please help!

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

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!

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 by GeeTR

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.

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?

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...

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 :D

guess mine is faulty

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

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.

:D

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

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.

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.

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...

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • 49719 is the cooler loop. Right at the front, LHS of that diagram. Return line from rack (LP side) goes to cooler loop on RHS front of car, then back under engine and returns to bottom of tank. 49717M is feed from tank to pump. HP line out of pump is thick rubber, followed by the hard line that runs down to crossmember and runs in parallel (but opposite flow direction) to the LP return line. Nothing goes anywhere near the firewall or interior of car. The closest they get to that is the connections on the rack.
    • Thanks, plan is to drain all fluid tomorrow and do smoke test to find out the leak.   Appreciate your help and want to understand how the system work. So cooling is achieved by the long loop not any rad? The diagram seems to suggest it connects to somewhere inside the cabin and I thought that is a cooler inside firewall. If you look at the diagram it seems to show it connects to something inside firewall. I tried chasing it but not easy unless I take loads off   i am confident pump is good as fluid goes in and it gets soft( steering) but as soon as I turn engine off , loads of bubble come to surface and overflow. When engine is on , fluid level is below minimum but when off it shoots off and thinking it is sucking air in. I suspect aluminium pipe may have a crack line or whole   smoke test with no fluid should be a good start and if needed will remove the pump   In addition, the one going under the engine bay is high pressure line and one directly connecting from pump to resorvoir is return/ low pressure?   finally I searched and suggestion is to use dexron 2 but that is discontinued so bought dexron 3 as all research suggest it is compatible and shouldn’t cause any issues/ blow seals. I bought two liter of dexron 3 motul atf
    • Don't worry about. Just don't try to drive hard enough to make boost and you'll be fine.
    • Yes. This has already been said. It is a loop of hardline in front of the radiator. Because.... the pump is on the LHS and the steering rack hydraulic connections are where they always are on a RHD steering rack....on the RHS. The high pressure line goes down under the engine, along the crossmember, like it does on all Skylines. Don't just throw expensive braided hoses/other kits at it. Work out what is wrong and fix that.
    • Still got the afm on the intake, clamps are shut tight, only loose hose is the one that goes from the j pipe towards the IACV, since it's next to impossible to find a factory hose and the barbs are different sizes (I'm still using clamps on this hose to try and help it seal on the iacv side) I've ordered parts to make up the hotside of the intercooler pipes, I'll plumb it in and see what happens in a few days I suppose The turbo's internally gated, can I just unscrew the tension rod to let the gate open?
×
×
  • Create New...