Oil Pressure Warning Light

[PA09M35X]

I purchased my 2009 M35X at the end of February this year with 48,000 miles. I now have just over 52,000 miles and I have been battling an oil pressure warning light for the past 6 weeks. It comes on and goes off with little or no regularity. It almost always shuts off for at least a few days after shutting the car down for an extended period of time. My local Infiniti dealer is stumped. I'm not experiencing any performance loss or horrific noises that would indicate major engine issues. The best guess from the dealer service department was that due to my change to Mobile 1 full synthetic oil, it may be breaking up sludge in the engine and that is getting stuck in the oil pickup, causing the intermittent oil pressure issues. Any other thoughts?

[jonlex99]

06 M35x with 87k miles. I been using Mobil 1 full sin tech EP with no issues. Get you local Infiniti dealer to fix it before you run out of warranty.

[PA09M35X]

That's the plan, but they don't know what to fix. Therein lies the problem. I was hoping to get some ideas. I had an '06 M35X that my ex is still driving. She has over 90k on it, never used synthetic of any kind, no issues whatsoever.

[mexillis]

If they think there could be sludge tell them to flush it or when draining the oil to check for it. I thought when the oil pressure light comes on is when you're running really low on oil? Anoher option yu can try is calling another dealership and see what they say. Just don't let it go past warranty coverage.

[PA09M35X]

Low oil levels can lead to low pressure readings due to the oil level dipping below the oil intake. However, my oil has been and remains at the 'full' mark on the dipstick. Low oil pressure can also be caused by clogged oil passages, bad sending units, etc. It's the intermittent nature of the problem that's puzzling to me.

[nbryan432]

@ PA09M35X I am having the same issue with my 2009 M35x. I bought the car recently and 3 days after the light came on. I brought it to their service center and the replaced the oil pressure sensor and by the time I reached home the light came back. So I brought it on last weekend but nobody can tell me what is the problem so I have been using a loaner they gave me until they do. But I am giving them until the end of this week and if they cannot fix it I am bringing it back to the dealer because Nissan is clueless as to what might be the problem. They are planning on sending it to Infiniti today.

[steve_c]

PAO,
I am assuming you have no warranty & you have no recourse, (Sold as is).

The blocked pickup theory does have some validity because you state on extended shutdowns all seems OK for awhile after initial start ups.
Can it be that sludge is dripping from the pickup back down to the pan via gravity on extended shutdowns?
If so, I would do a few OFC's (dino oil of course) to see if that sludge might be removed during the process.

Step one for me would be to verify the oil pressure is truly low vs an electrical gremlin or a sending unit problem.
If I owned your M, I would verify the oil pressure is truly low by hooking up a mechanical gauge to an oil port on the engine.
You could Tee-off from the low oil pressure switch, but if another port were available, I would rather use it.

Regarding other usually experienced low oil pressure symptoms,
A marginal oil pressure condition (light barely stays out) that gets worse when the engine oil reaches it operating temperature (light comes on).
On cold starts, all would be OK until engine reaches operating temp, then light comes on....your not experiencing this I think from your OP

Another (similar to above) low oil pressure symptom would be, all OK when cold, but when engine gets to operating temps,
light comes on when in idle, (low RPM) and goes off on acceleration, (higher RPM).
You do NOT seem to have those symptoms either!

48k miles is truly low mileage as far as the longevity of these engines go. I would try a few engine oil flushes to dispel the possibility sludge.

[nbryan432]

So I got a call from the Dealer this morning from General Manager who was asking me status on the car because he thought the car was fixed from Monday of this week but when I told him it is still at the service center he told me told me to hang. So 1/2 hour after the service center called me and start spilling their guts on the status of the car. Infiniti told them to bring the car to their service center and they are replacing all the sensors that they think would possible gone bad. So I will let you all know the status when I get the car back.

[steve_c]

nbryan,
You purchased the car from the Infiniti dealer that is looking into the problem?
I am assuming so, as it seems they are doing the right thing to get the problem solved.
Please keep us posted, & good luck!

[nbryan432]

Yes I bought from them so I have 3 years warranty so that's the good part. I should hear from them today or Monday so I will keep you updated

[nbryan432]

ok Guys sorry for the late reply so I got back the car almost 2 months now with no oil lights. They had to replace the computer because it was sweating on the circuit whenever the rain falls so from the replace it I have not seen from then.