SE-R Oil Pressure

There is another post just a few threads down about someone who has this problem. You've gone a step further and actually put a oil pressure gauge on the car. The spec according to the manual I have and my alldata account is 5PSI at idle. So you are pretty much right there. If you're idling a smidge low, that might account for the 1PSI difference. I recommended to the other person to try a idle re-learn.

http://www.nissanclub.com/forums/1570334-post1.html


As suggested, definitely check your oil level.

Oil type and age play a big factor in oil pressure on this motor. Factory spec is 5W-30. I've found that after a oil change, at idle, I'll actually register a small pressure on my dash pod gauge. But after approx. 3000 miles, my gauge is no longer reading anything at idle. I make sure to go no more than 3000 miles between oil changes, appearantly the oil breaking down over that mileage affects the motors ability to make good pressure at idle.


EDIT:
The thing I would be concerned with is your pressures at different RPM's. The other spec my alldata account shows is 43PSI @ 2000RPM. You are not even close to that, so that concerns me a little.

If you haven't had this car long enough to do an oil change, make sure you do that and put 5W-30 in to start. (4.5QT with oil filter)
Also, splurge on a Nissan Oil Filter

Thanks for your quick reply. I just finished the idle relearn procedure.It already seem to idle 50-100 rpm higher. Perhaps this will prevent the oil light to go on.


What can cause my pressure to be that low at 2000 rpm?


for reference the in dash oil gauge is showing this:

idle : almost if not 0
2000rpm: At 75% between 0 and 1/4 mark.
3000 rpm: At 75% between 1/4 and 1/2 mark.

Plase note that it is a canadian car so oil gauge reads like that:
1/4 mark is 200 kpa
1/2 mark is 400 kpa
3/4 mark is 600 kpa




Edit: the oil was change 2 week ago with penzoil platinium 5w30 with a napa gold filter. Also the oil was checked before the oil pressure test.

I too use Pen. fully synthetic 5W-30. I thought I was doing my car a favor by using it but now I'm not so sure.

Anyways, if you just changed it you shouldn't be getting readings that low. You probably shouldn't be getting readings that low anyway. That 25PSI reading at 2000RPM, was that by the oil pressure gauge on the motor or was that by your dash gauge? If by your dash gauge, double check that against a pressure gauge connected to the motor. If that reading was off of the motor pressure gauge, I would be a little concerned, probably think about geting rid of the car soon he he
There are quite a few threads on these boards about people who have had oil pressure problems and alot of them had their motors replaced by Nissan. At least those who still had a warranty. It could be your oil pump is starting to go. I also wouldn't 100% rule out the oil pressure sending unit as faulty, though usually when they go bad you get no reading or wacky/erratic readings.

I believe the oil pump can be changed by just pulling the lower oil pan? Let me go check......
yikes, nope. It looks like the timing cover needs to be pulled. It seems to be "behind" where the crank pulley would go. Looks like the "upper" oil pan also needs to be taken off. You more or less have to drop the motor to do that job. It's not 100% necessary, but definitely the way to go. The diagram I looked at also has a "regulator valve" "regulator spring" "regulator plug". I do not know if this plug is accessible from under the engine or by just pulling the lower oil pan. This might be a item to do research on, perhaps this may be faulty and you could just pop those pieces out and replace them. This is just guessing, I have never read any info on doing this.

Thanks for your help swamper.

Yes the 15 [email protected] was taken with a gauge directly attached to the motor. (it is an old harbor freight gauge...)

The center pod gauge is reading 21psi @2000rpm and 50psi @3000rpm


Is it easy to drop the oil pan? perhaps the oil pump pickup is obstructed...
I also read that the timming chain cover gasket could be bad causing pressure lost.

I dont know were to start.

I wouldn't go too crazy with thoughts of replacing the motor quite yet. There's lots of diagnostics that can be done before that. First off, if you're not burning oil, then you don't have damaged cylinder walls. The entire health of the motor can be checked without dropping the motor. If you want to know the general health of the block/heads, you can:

1.) perform a compression test. This would require pulling the upper manifold and all 6 coil packs. Using a compression gauge (follow instructions that come with it) you can see the compression developed by each cylinder. Each cylinder should meet a minimum value (check manual) and each cylinder should be within a certain % of the others. The only kicker with the compression test is that it should be done with the engine warm. But taking the upper intake and coil packs off takes time. If you're going to do that, I would suggest first taking off the rear support bracket for the upper intake manifold. that is the piece that is the hardest to get off and you don't want to do it with the motor hot. After that bracket is off, THEN warm up the engine, remove the upper mani/coil packs/spark plugs and proceed with the compression test.

2.) Though a little more involved (and takes more knowledge) you can do a LEAK DOWN test with a leak down gauge. This involves checking each cylinder, one at a time, making sure you spin the crank shaft so that both valves are closed for the cylinder being tested. A leak down gauge connects to a compressor (regular air compressor) and pressurizes the cylinder. If you have bad piston rings/damaged cylinder walls, air will leak down into the crankcase and out a easy path (usually you'll feel air coming out of the dipstick tube/hole) If you have a bad intake valve seat, air can be felt coming out the intake. (take the intake tube off, hang a piece of tissue paper off the throttle body and watch to see if air escaping moves the tissue paper around) Same with the exhaust valve. If you have bad exhaust valve/seat, you can use the same tissue paper on the tail pipe and see the air leaving.

If you plan on doing the job yourself, you're probably just better off getting a low mileage motor from a bone yard. (500-1500 is good) But before I ever spent 8000 on a motor from a stealership, I'd expect some serious serious diagnostics be done first.

As far as donor motors, I go to car-parts.com and search for parts. It checks the inventory of all junkyards in the system. I have several actual SER motors around me. I've also been told in another post that a 6th GEN Maxima engine is pretty much the same motor. I believe even a regular 3.5 SE motor is the same. The SER has only +10HP over the SE and that is ECU and/or exhaust gains, nothing internal to the motor.

a little FYI for the OP, instead of/in addition to the Lucas additive you could also raise your target idle RPM as well. On a seemingly unrelated topic, I've been looking into the AUTOENGINUITY scan/diagnostic tool and the UPREV CIPHER scan/diagnostic tool. Both claim the ability to perform the following hard code changes to your ECU:
1.) Timing +-2 degrees
2.) Erase learned fuel curves/maps
3.) Idle Re-learn
4.) Raise/Lower idle +-250 RPM

Uprev Cipher is probably the better deal at $200. a few extra hundred RPM might bring the oil pressure up a few PSI while sitting at traffic lights etc

EDIT:
Well I’m going back through and editing everywhere I’ve recommended the Autoenginuity scan tool. At least for monitoring A/F anyway. I went ahead and purchased the scan tool only to find out it doesn’t play well with the Nissan ECU’s. So I was not able to see actual A/F ratios with the tool, only raw voltage/current levels from the sensors. I worked with their tech support for a few days to try and figure out what was going on (they thought it should work fine) but at the end we weren’t able to get that feature working. All in all the scan tool is a good device and you can monitor, activate/de-activate many other sensors/signals and functions, but for the purposes of using it as a A/F tuning tool (alternative to stand-alone A/F gauge) it can’t do it.
I have confirmed with Uprev tech support that their Cipher scan tool can interpret/present A/F ratios on screen, so my next investment will be to get Cipher and confirm this.