Alright guys, let me start off by saying I HAVE looked at older threads on this site for answers to my question, but most OP issues arent the same as mine. I have a 2006 350z 6SPD MT with around 111xxx miles. Ive had the car since around 105xxx, and this issue never really arose until about a few weeks ago. I recently had an oil change and put 5w30 mobil one synthetic in. Had low oil pressure before that and the new oil seemed to fix the problem. (Had low oil reading on dipstick). Now, if im in gear and brake almost to a stop before i put the car in neutral, oil pressure reading on the gauge drops almost to 0 and the light will come on for a split second. When i begin to accelerate again, the PSI reading goes up to around 60, and will drop and be steady around 30. Slowing down seems to lower the pressure, and speeding up raises it. Its not steady like it used to be. I checked my oil and it seemed a little low, so I added a quart a few weeks ago and the light never came back on, but now its doing it again. Also, braking hard will cause severe drops in oil pressure. Might be a fault in the sensor?

 

https://my350z.com/forum/engine-and-...ml#post9115004

I did a search and want to try 0w30...I always have used 5w30.

Do you have a VQ35HR motor?

http://www.mobiloil.com/usa-english/...ilOption2.aspx

 

Sounds like you might have an oil consumption issue - many of the 05-06 Revup motors had it.

https://my350z.com/forum/engine-and-...iscussion.html

 

The drop in oil pressure when braking is due to the oil pump slowing down when your RPMs drop. It is normal (once the car is at normal operating temp) for the oil pressure to be very low at idle and increase as your RPMs increase.

I'd keep checking your oil level as it seems you tend to lose quite a bit. When your oil level is low, it is more likely to 'slosh' around as you accelerate, decelerate, and corner, so when you're braking, the oil is likely moving away from the pickup.

Please add more details about your car. In particular the year...

 

Year is posted (06)

 

I'm not suggesting you buy this oil pan, but this site has some good pictures of the OEM pan and pickup that may help you understand what's going on.

http://www.airpowersystems.com/350z/sump/sump.htm

It's hard to imagine that the oil movement of normal driving or even normal aggressive driving would cause the oil to move far enough to cause the pump to starve if the oil level is anywhere close to what's recommended.

I wish Nissan used self-adjusting oil pumps like the one in my '00 Silverado. It varies just a little between 70 and 75 psi, but I've never seen it outside that range regardless of engine speed, operating temperature, or ambient temperature. The pressure in the Z varies between 30 (hot idle) and 110psi (cold start).

 

If you are cruising at 2500 RPM's does oil pressure stay steady or gradually fall to 30?
Using 2500 RPM's as a reference, in other words if your rpm's stay steady does the oil pressure stay steady at 60psi or gradually drop to 30psi?

And is your engine making and noise, ticks or rattles?

 

Have you checked the electrical connector to the sending unit?

 

@gunsmoke, the oil pressure stays around 30psi cruising normally around 2500, but if I brake hard it drops almost to 0 and will rise when I accelerate.
No noises.

 

I'm actually having a similar problem. When I'm in neutral or in low rpm, the oil pressure is almost touching the 0, when I pick up, it will get above 30 but unless if I'm in 4-5,000 range it will not surpass 60. I did an oil change, I had the camshaft sensors replaced, the idle reprogrammed and now there is no check engine light but the oil appears the same on the gauge. They replaced the solenoids in the valve timing covers as well. I originally had a p0021 and then a p0011, can anyone chime in on this? The car is a 2007 manual.

 

I'm just saying that if the levels are severely low, then any movement could starve the pump.

'06s are known for their oil consumption issues already, so if you add in 110k miles of wear and tear, he could be losing a significant amount.

To answer the others, yes, the difference in oil pressure between idling and 2500 RPMs and above is significant. At a constant RPM, your pressure shouldn't be dropping very much, if at all.

 

Just as an FYI, I paid attention to my readings on the way home last night.

Once the car was at normal operating temp:

• Idle at stoplights - ~40-45psi
• Freeway speeds (2000-3000rpms) - ~70-80psi

Pressure would not decline at all while at a steady pace.

 

I keep any extra quart in my car now xD And my friend suggested using 30w instead of 5w-30?

 

I don't think straight 30w is good for our cars, they aren't lawnmowers, try 10w40, I think it says in warmer climates it can be used (check manual to make sure, mines not handy) but that's as far as i'd want to go.

Before I went too nuts I would check it with a manual gauge, sending unit or gauge could be screwy, My sisters Mini was actually leaking thru the sending unit into the connector and did the EXACT same thing, its a known issue with them, just something to toss around before you experiment too much. Plus a mechanical gauge doesnt lie.

 

Ok thanks I will look into that