Oil Pump failing?
12-19-2015, 08:15 PM
#1
Oil Pump failing?
High oil pressure after an oil change, got the sensor tested and it is working and continued with a pressure test.. It is idling at 24psi and at 2500 rpm it is at 60psi . I am driving cross country with it so i do not know. So thats 70 mph i believe , when i push it up to 80 mph i get to 76ish psi but over a little bit of time it drops back down to 60-65 psi. That makes me scratch my head. So is it a blocked gallery, semi closed pressure relief valve ? When i start it cold it goes almost to 120psi. Let me know what you guys think.
12-20-2015, 08:03 PM
#8
With cold oil, yes. I take it easy on the revs until the oil pressure gets down into its Normal range, which is a good indication its at normal temp. The Z doesn't have an oil,temp,gauge, but on my cars which do, this is easy to observe. As soon as my Z's warranty expired last May, I also switched to Mobil 1 0w-40, which minimized those swings in pressure between a hot and cold engine. Really, you're overthinking this, and your engine is right on-spec for 5w-30 and your climate.
12-22-2015, 08:29 AM
#9
With cold oil, yes. I take it easy on the revs until the oil pressure gets down into its Normal range, which is a good indication its at normal temp. The Z doesn't have an oil,temp,gauge, but on my cars which do, this is easy to observe. As soon as my Z's warranty expired last May, I also switched to Mobil 1 0w-40, which minimized those swings in pressure between a hot and cold engine. Really, you're overthinking this, and your engine is right on-spec for 5w-30 and your climate.
12-22-2015, 09:18 AM
#10
I still think you're crazy. The FSM states the oil pressure should be >14psi @ idle speed and >43psi @ 2000rpm, with the engine oil at 176F. No max numbers are provided.
If you're driving around with warm oil at 60-65psi, the relief valve isn't sticking. If you want to be as **** about it as I am, change to the Mobil 1 0w-40.
If you're driving around with warm oil at 60-65psi, the relief valve isn't sticking. If you want to be as **** about it as I am, change to the Mobil 1 0w-40.
12-22-2015, 10:00 AM
#11
I still think you're crazy. The FSM states the oil pressure should be >14psi @ idle speed and >43psi @ 2000rpm, with the engine oil at 176F. No max numbers are provided.
If you're driving around with warm oil at 60-65psi, the relief valve isn't sticking. If you want to be as **** about it as I am, change to the Mobil 1 0w-40.
If you're driving around with warm oil at 60-65psi, the relief valve isn't sticking. If you want to be as **** about it as I am, change to the Mobil 1 0w-40.
12-29-2015, 05:16 PM
#12
Update. Drove my 3500 mile road trip,observed a few things.
-Cold start up around 110psi - 40-50 outside temp
-Operating temp at 65-85mph 65psi
- Around 2,000 miles in I was getting more engine vibration/noise at idle.
-The main odd part of it was, I could start my drive and I would be at operating temp by the time i got on the highway, accelerate to 65 and lock cruise control . The oil PSI would be at 75~ . Then after 30 minutes or so go down to 65psi~ . Then I would bump it up to 80 and it would climb to 75~ psi again for 10 or so minutes then go down to 65 psi ~ . The only odd part was when id WOT in 6th gear going 80 the PSI would drop down to or below 60 for a brief moment the start building up. Anthing past 4k rpm would be past 90psi which the techs at nissan said dont go past. Modderate acceleration the PSI would needle would "wiggle" up and down in PSI on initial acceleration then smoothly build in PSI.
-Current action , drain oil and take a sample to send to a lab. Take off oil pan and inspect the oil pump pick up for build up and try to visually inspect the galleys. Will keep updated if anyone is interested.
-Nissan quote , $100 for inspection then further action up to me. Oil pump replacement at a shop $1,000+.
-Currently in VA beach if anyone local wants to help trouble shoot with me or give a second opinion in.
-Sorry if to some of you this seems like a non major issue but this is my first car i paid for out of 100% and i baby the thing so if something minor/major goes wrong i toss and turn in my sleep.
-Cold start up around 110psi - 40-50 outside temp
-Operating temp at 65-85mph 65psi
- Around 2,000 miles in I was getting more engine vibration/noise at idle.
-The main odd part of it was, I could start my drive and I would be at operating temp by the time i got on the highway, accelerate to 65 and lock cruise control . The oil PSI would be at 75~ . Then after 30 minutes or so go down to 65psi~ . Then I would bump it up to 80 and it would climb to 75~ psi again for 10 or so minutes then go down to 65 psi ~ . The only odd part was when id WOT in 6th gear going 80 the PSI would drop down to or below 60 for a brief moment the start building up. Anthing past 4k rpm would be past 90psi which the techs at nissan said dont go past. Modderate acceleration the PSI would needle would "wiggle" up and down in PSI on initial acceleration then smoothly build in PSI.
-Current action , drain oil and take a sample to send to a lab. Take off oil pan and inspect the oil pump pick up for build up and try to visually inspect the galleys. Will keep updated if anyone is interested.
-Nissan quote , $100 for inspection then further action up to me. Oil pump replacement at a shop $1,000+.
-Currently in VA beach if anyone local wants to help trouble shoot with me or give a second opinion in.
-Sorry if to some of you this seems like a non major issue but this is my first car i paid for out of 100% and i baby the thing so if something minor/major goes wrong i toss and turn in my sleep.
Last edited by Sailors350Z; 12-29-2015 at 05:17 PM.
12-31-2015, 02:50 PM
#13
Update.
-Brought the car to a 28 year Nissan Vet. He's scratching his head
- His suggestions are PCV valve change , Engine Flush , Pressure relief valve in the oil pump.
- Replaced PCV Valve. No Change . No change in oil PSI
- Got an engine flush and oil change. No change in oil PSI
- For anyone interested. Engine RPM to PSI readings.
- idle 400~rpm 15psi~
- 1k 30 psi
- 1.5k 40 psi
- 2k 55 psi
- 2.5K 65 psi
- 3k 85 psi
- 3.5k 90~ psi
- 4 k 100 psi
- 4.5k 110psi
Manufacturer Spec idle 14 psi 2k rpm 43psi (min. , warm engine)
-Brought the car to a 28 year Nissan Vet. He's scratching his head
- His suggestions are PCV valve change , Engine Flush , Pressure relief valve in the oil pump.
- Replaced PCV Valve. No Change . No change in oil PSI
- Got an engine flush and oil change. No change in oil PSI
- For anyone interested. Engine RPM to PSI readings.
- idle 400~rpm 15psi~
- 1k 30 psi
- 1.5k 40 psi
- 2k 55 psi
- 2.5K 65 psi
- 3k 85 psi
- 3.5k 90~ psi
- 4 k 100 psi
- 4.5k 110psi
Manufacturer Spec idle 14 psi 2k rpm 43psi (min. , warm engine)
12-31-2015, 03:39 PM
#14
I'm going to tell you one more time there's nothing wrong with your engine, and also add that those numbers you just posted weren't with the oil fully up to temp. The numbers you posted during your cross-country drive are different, absolutely fine, and in that case the oil certainly was warm. You need a car w/o a pressure gauge 
, and there's a good reason most cars don't have one.
, and there's a good reason most cars don't have one.
12-31-2015, 04:19 PM
#15
I'm going to tell you one more time there's nothing wrong with your engine, and also add that those numbers you just posted weren't with the oil fully up to temp. The numbers you posted during your cross-country drive are different, absolutely fine, and in that case the oil certainly was warm. You need a car w/o a pressure gauge , and there's a good reason most cars don't have one.
, and there's a good reason most cars don't have one.
12-31-2015, 10:19 PM
#16
A "used" Z may not be the best reference. A beat one might have lower pressure, or the incorrect oil, and, if you don't drive it for at least 20 minutes to half an hour you won't get the oil up to temp. I'm in FL, and that's how long it takes on my cars with oil temp gauges (Alfa and BMW).
01-01-2016, 10:16 AM
#19
Most engines require about 10 psi of oil pressure for every 1000 rpm of engine speed. This applies to ordinary passenger cars as well as race cars like NASCAR.
So on your 350Z, if it revs to 6000 rpm, 60 psi would be about right.
If you are getting 110 to 120 psi at 2500 to 3000 rpm, the oil pump pressure relief valve is stuck and is overpressurizing the system. Your engine can probably handle 80 to 100 psi with no problems, but the concern is the oil filter and the plugs in the oil galleys. Too much oil presure may caue the filter and/or plugs to blow out. That would be really bad news because all the oil woulde blow out, your engine would starve for lubrication and probably seize.
Read more: http://www.justanswer.com/car/0uyqe-...#ixzz3w1Q5oT00
So on your 350Z, if it revs to 6000 rpm, 60 psi would be about right.
If you are getting 110 to 120 psi at 2500 to 3000 rpm, the oil pump pressure relief valve is stuck and is overpressurizing the system. Your engine can probably handle 80 to 100 psi with no problems, but the concern is the oil filter and the plugs in the oil galleys. Too much oil presure may caue the filter and/or plugs to blow out. That would be really bad news because all the oil woulde blow out, your engine would starve for lubrication and probably seize.
Read more: http://www.justanswer.com/car/0uyqe-...#ixzz3w1Q5oT00