mechanic says its good... (low oil pressure warning)

[r3ccOs]

This mechanic however was the one who shoehorned this engine in my 05' Altima SE-R (VQ35DE) as mine was shot

the oil pressure warning light only comes on after the car's been driven for about an hour or so and only at idle in "drive"

if its in park or neutral, or if there engine is any higher than 500rpm, it goes away

the gauge seems to be working, but it could be a sensor problem (hoping) and the mechanic checked the oil pressure and he says its kosher

its just kinda disconcerting, the car doesn't make any noise, but i don't want to blow the crank bearings...

being that the idle drops to 500rpm (which is about 200 lower than neutral) and I recently had serviced the transmission, could it be like a torque converter issue, causing the engine to bog?

[RickDaTuner]

Worn main bearings would be my guess, all 02 and newer engines should be running at least semi synthetic engine oil, the timing chain tensioners are prone to gunking and causing chain slap that results in block erosion and metal through out the cam journals and main bearings.

The definitive test of low oil pressure is hooking up a manual gauge either to a block galley plug, or an oil filter sandwich adapter.

[r3ccOs]

that sucks, i've been using nothing but synthetic and its just off warranty :(

it has about 50k km on it

the timing phasers had went on the old engine, and this was apparently a better way to go... but apparently not :(

where is the block galley plug? the mechanic said he did do a oil pressure test on it, and is blaming the sensor (but the sensor is working, meaning it goes off and on, and the gauge is reading)

[DeleriousZ]

I'd definitely replace the sensor before anything else. If the mechanic checked it, he most likely used a mechanical gauge. I know on my cars, the pressure sensor dies on the reg.

[r3ccOs]

anyone recommend a good nissan tech or shop?

[r3ccOs]

based on the gauge in the car, i can see the oil pressure is where its supposed to be at various RPM ranges and loads

i know its not the most accurate, but that to me means this is not an oil pump, and in this case its crank driven and is a big deal if it was.

I did a idle relearn, which has raised the RPM back to 700 properly, but when I drop the car back into drive, from neutral or park, and only when the car is really warm, it will still give that low oil pressure light until its rev'd and comes back normal

I hope its a sensor, but if it is a camshaft bearing, what other type of signs would I be able to tell? I've googled and there is no knock coming from the engine at all, just the injectors firing is the only kind of tick

[BerserkerCatSplat]

Originally posted by DeleriousZ
I'd definitely replace the sensor before anything else. If the mechanic checked it, he most likely used a mechanical gauge. I know on my cars, the pressure sensor dies on the reg.

X2, do the sensor first. Sending units die all the damned time and people freak out. If the mechanic said it was good with a mechanical gauge, I wouldn't start worrying too much yet.