Low Oil Pressure

[Wacky Dee]

About a year ago I noticed my oil pressure factory gauge showing very low oil pressure as I was driving (about 1kg/cm2) and on warm idle. The next day it went away so I always assumed the sender may have been dodgy. I hadn't driven the car for the past 6 months and only started driving again recently (a week or so) and I've noticed that on cold start the oil pressure gauge shows barely 4kg/cm2 when it used to show 6kg/cm2 on cold idle.

When warmed up now it drops to 1kg/cm2 or a bit lower when idle but climbs up to 2.5-3kg when driving under light load. Now I know from reading on these forums and from my mechanic that the oil pressure sensors are notoriously unreliable but I don't want to take any chances and destroy my engine.

I've put new oil and filter yesterday (royal purple + nissan filter) and nothing's changed. The car seems to run normally and according to mechanic (Yavuz) the engine sounds healthy and it's most likely a busted sender unit/sensor. But again I'd like to be sure as I've almost stacked it today on the motorway watching the gauge..

So what's the cheapest and easiest way for me to check if it's just the factory sensor that's busted or something more serious ? Few things..

1) I have a Consult cable + software (datascan) Is it possible to check health of factory sensor using consult/datascan at all ? Like checking the voltages of the oil pressure sensor at certain RPMs or would that be pointless ?

2) I have a slight leak on my rocker cover near the firewall. From what I've found out this is quite common and usually nothing to worry about. Could a rocker cover leak be affecting oil pressure levels at all ??

3) Does anyone have an accurate oil pressure gauge I could borrow to test my oil pressure ? I don't want to buy one of the cheapies as they can be inaccurate (I know my aftermarket water temp gauge is very inaccurate for example). Nissan wants $250 for a new sender unit so that's kinda out of the question.. How hard is it to attach an aftermarket oil pressure gauge ? Anyone done it? I think I'd need to buy one of those adaptor plates that sit under the oil filter and attach the electrical gauge to that .. how hard would this be considering I've next to no tools or space to work ? Don't wanna make a mess with oil spilling everywhere either

Yeah I know ...that's a lot of stuff I've written and asked, just trying to be thorough so you have a good idea of what I'm up against. Cheers

Dee

[NewKleer]

oil pressure isnt available via consult

[Wacky Dee]

aaaaaaaanyone?

[mosquitocoils]

Hey mate... The rocker cover leak probably would not be affecting your oil pressure that much although it does seem to make sense that it would. I had the same problem, changed the gasket and no change. Changed oil twice and pressure holds perfectly now..... go figure? That was about 6 months ago and it still hasn't changed.

I think to get a sandwich plate under the oil filter, you need a relocation kit as well. Could be wrong, but I do know that's the setup I've seen on most skyrines.

The other option would be to hit up an import wrecker and buy another second hand sender, although it may not be much help considering it's age and the circumstances of it's life too.

[Galois]

hey mate, as you said the gauge is pretty inaccurate.

i notice a HUGE difference in oil pressure behaviour during hot/cold/idle/load driving. im doing 1000km changes of oil+filter cos my oil keeps coming out black (thanks previous owner for not taking care of the engine) and i don't want to use a flush for various reasons. each filter/oil has different resting points. now with that nulon "synthetic" stuff and a drift filter it's sitting just below 2 on idle, maybe at 1.7-1.8, but im changing this weekend. 700kms ago idle was at 2.5.

if you're concerned, do another oil change at 1000km. as suggested above, it might take a few oil changes to level out. maybe the sensor just needs new oil washing over it...

[Wacky Dee]

ok thanks guys I'll try doing another oil change soon .. although the motul that was sitting in the car for 6 months was brand new as is the new royal purple. But you never know it might be gunk stuck on the sender. I just hope it's the sender unit and not my actual oil pressure thats out of whack.

[BASHO]

$250 ? Fark me that seems to be Nissans bottom line for everything over 50 bucks, nah call it--well erm--yer $250 two poxy inernal air filters --$260-- O2 sensor eeerrr--yup $260'll be about right.

If you take it to any decent workshop they should be able to run an acurate pressure gauge out of the sensor hole for not to much moolah andd they could clean the sensor for you before they put it back in or get a live feed gauge from Supercheap or whoever take out the sensor and hook it up to the sender hole yourself --and give the sensor a rub a dub before you put it back , then flEBay the gauge when you've done.

[Wacky Dee]

Thanks for the tips. Where is the actual sender located ?? Is it easily accessible via engine bay or do you have to remove the oil filter first etc ?

[BASHO]

Thanks for the tips. Where is the actual sender located ?? Is it easily accessible via engine bay or do you have to remove the oil filter first etc ?

To be quite honest and at a quick glance I'm not sure, there's a sensor to the right of and just behind the oil filter however I don't know whether that is the dash oil sensor light only or the oil pressure gauge and the dash warning light as well.