Patrol 4x4 - Nissan Patrol Forum banner

21 - 32 of 32 Posts

·
Registered
2010 GU DX CRD Grenade :)
Joined
·
526 Posts
Righto. Have you got an oil pressure gauge on yours? Or have you had it checked with a known good gauge?
 

·
Registered
Joined
·
9,305 Posts
I don't know whether this goes on voltage or pwm signals to the ecu, but I have no way of testing it. According to the snippets from the manual, that should put the light on if the values don't match what the ecu is looking for.
Regards the sensor, they are a single wire so I assume it is a simple resistance measure as it is earthed directly to the block. The same with the switch is single wire and makes contact when the pressure drops.


The 10psi at low idle isn't looking fantastic, but seems to be a regular pattern, on here at least...
I have also been wondering about the valves on the cooler. Initially when I put the rebuilt motor back in, I had the rubber covers off from inside the wheel arch. That was to make access to oil filter and other connections easy to check for leaks etc. It also meant I could hear a lot more of the engine noises than previously. There is a strange buzz rattle sort of noise from around the oil cooler bypass valve. It is only apparent when coolant temperature is above 86C.
My new motor is very stable on temperature during driving even with fairly hard work towing a trailer, but then when I get back home and reverse the trailer up the driveway, the coolant temp climbs very slightly to 86 or 87C. It is then that I stop to let it idle and cool down, I can hear the buzzz noise from the cooler. This seems to stop as the motor cools below 85C. I don't know if temperature has anything to do with the valve operation. I think it is a simple ball bearing and spring. But I do wonder if it acts differently when oil temperature is high. I might have to put a temp probe on it to test oil temp rather than just coolant temp.



Ross does the switch have just a single wire like the one on Mine has on the turbo side. I assume that yours does then not have the other sensor, although I don't really know what it is doing on mine anyway.
 

·
Administrator
GUII ZD30DI Wgn
Joined
·
44,160 Posts
Regards the sensor, they are a single wire so I assume it is a simple resistance measure as it is earthed directly to the block. The same with the switch is single wire and makes contact when the pressure drops.




I have also been wondering about the valves on the cooler. Initially when I put the rebuilt motor back in, I had the rubber covers off from inside the wheel arch. That was to make access to oil filter and other connections easy to check for leaks etc. It also meant I could hear a lot more of the engine noises than previously. There is a strange buzz rattle sort of noise from around the oil cooler bypass valve. It is only apparent when coolant temperature is above 86C.
My new motor is very stable on temperature during driving even with fairly hard work towing a trailer, but then when I get back home and reverse the trailer up the driveway, the coolant temp climbs very slightly to 86 or 87C. It is then that I stop to let it idle and cool down, I can hear the buzzz noise from the cooler. This seems to stop as the motor cools below 85C. I don't know if temperature has anything to do with the valve operation. I think it is a simple ball bearing and spring. But I do wonder if it acts differently when oil temperature is high. I might have to put a temp probe on it to test oil temp rather than just coolant temp.





Ross does the switch have just a single wire like the one on Mine has on the turbo side. I assume that yours does then not have the other sensor, although I don't really know what it is doing on mine anyway.
One wire to the single pressure sensor.
 

·
Registered
2010 GU DX CRD Grenade :)
Joined
·
526 Posts
Regards the sensor, they are a single wire so I assume it is a simple resistance measure as it is earthed directly to the block. The same with the switch is single wire and makes contact when the pressure drops.




I have also been wondering about the valves on the cooler. Initially when I put the rebuilt motor back in, I had the rubber covers off from inside the wheel arch. That was to make access to oil filter and other connections easy to check for leaks etc. It also meant I could hear a lot more of the engine noises than previously. There is a strange buzz rattle sort of noise from around the oil cooler bypass valve. It is only apparent when coolant temperature is above 86C.
My new motor is very stable on temperature during driving even with fairly hard work towing a trailer, but then when I get back home and reverse the trailer up the driveway, the coolant temp climbs very slightly to 86 or 87C. It is then that I stop to let it idle and cool down, I can hear the buzzz noise from the cooler. This seems to stop as the motor cools below 85C. I don't know if temperature has anything to do with the valve operation. I think it is a simple ball bearing and spring. But I do wonder if it acts differently when oil temperature is high. I might have to put a temp probe on it to test oil temp rather than just coolant temp.





Ross does the switch have just a single wire like the one on Mine has on the turbo side. I assume that yours does then not have the other sensor, although I don't really know what it is doing on mine anyway.
Yours is a di isn't it? On my crd, that pressure sensor on the right hand side has a plug with what looks like 3 wires in it. I assume this is so it has variable pressure depending on rpm and mentioned in the workshop manual.

As for the di, I couldn't say. It seems strange they would run 2 pressure switches on the later model ones.
 

·
Administrator
GUII ZD30DI Wgn
Joined
·
44,160 Posts
One switch is high pressure the other low pressure.
 

·
Registered
Joined
·
9,305 Posts
Yours is a di isn't it? On my crd, that pressure sensor on the right hand side has a plug with what looks like 3 wires in it. I assume this is so it has variable pressure depending on rpm and mentioned in the workshop manual.

As for the di, I couldn't say. It seems strange they would run 2 pressure switches on the later model ones.
OK so the CRD sounds like it has changed to an actual pressure transducer if it has three wires. My Di 2005 as Ross said just has the two switches, each is only a single wire so open or closed contact and a resistor thing behind the drivers side kick panel.
 

·
Registered
2010 GU DX CRD Grenade :)
Joined
·
526 Posts
Ah ok, fair enough. The manual page posted earlier is from the crd, that's why the rpm and pressure scale is on there. According to that, if the ecu doesn't get the pressure it is expecting at a given rpm, it puts the oil light on. That more detailed page may have been posted in one of those other threads...

Driving around a bit this morning, I'm more and more convinced of the 20psi for 1000rpm thing. Toddling along at 1500rpm was flat on 30psi on the gauge, still 40psi at around 2000rpm. These are at normal operating temp, just cruising around at 50 or 60 KS, depending on the speed limit obviously...

I'm not overly fussed about the low reading anymore at idle, whether it is a problem as you mentioned above, with the oil filter and cooler setup with the bypass or a problem with the relief valve, well I guess that's not going to be easy to diagnose...
 

·
Registered
Joined
·
9,305 Posts
This is an interesting bit of information from the CRD update. I see they say to only take oil pressure measurements from the starter motor side. I am still not sure why there would be any difference as this point is directly connected with the oil galleries from the other switch. The switch (on the turbo oil feed for the Di) at the oil cooler is the first outlet of the oil filter so is before the second oil switch sensor point near the starter.

The only think that I can think of for my Di, I have the oil pressure gauge from the left side near oil filter, this is the point on the turbo oil feed and low pressure switch. Possibly oil flow into the turbo can drop oil pressure at idle when there is limited volume flow from the oil pump. But the CRD has the turbo oil feed at a different point after the oil cooler, so I don't think that possibility is as likely explanation.

If I get enthusiastic for some contortionist exercise, I might get to crawling in under the starter motor and changing my gauge sensor to the other side and test. Not too keen on that idea though.



517375
 

·
Registered
2010 GU DX CRD Grenade :)
Joined
·
526 Posts
Thought I'd throw up some pics, all in neutral just free revving. I had been driving for about the last 10 min, so fairly well warmed up. The other gauges are a bit blurry because it is so bright outside... Trying to get the tacho properly visible more than anything...
IMG20200326134327.jpg
IMG20200326134337.jpg
IMG20200326134342.jpg
IMG20200326134350.jpg
 

·
Registered
Was known as JT54_Y61 GU IV 08CRD Wag ST
Joined
·
159 Posts
In addition to @geordie4x4 post #28 above, the following is an extract from the CRD TM1

Oil Pressure is monitored via the ECM with the utilisation of an Oil Pressure Sensor which is located at the RH rear of the engine. In addition to the Oil Pressure Sensor there is an Oil Pressure Switch located at the LH front of the engine, above the oil filter. This switch will ground & illuminate the ‘red oil can’ warning light when there is close to 0 Oil Pressure. The Above mentioned Oil Pressure SENSOR is connected directly to the ECM. If the ECM measures specific pressures at certain engine speeds & temperatures, the ECM will signal the Instrument Cluster to illuminate the RED OIL CAN warning light on the Instrument Cluster.
Have provided my 08 CRD ROM Results - take off (pressure) @ sensor port (near starter motor) 08 CRD 170,000 kms. Using VDO elec gauge (calibration status as OEM supplied):

Oil used 10W40 Semi Synthetic_Nissan Supplied, since new (change every 5000-7000ks _ no noticeable usage)

Cold
Start @ Idle 750RPM approx 600 kPa (nom 90 psi)

Hot _ Eng under load (nom 50%) except for idle @ end of 100km rnd trip to get veg today.
@ Idle 750 RPM / 100 kPa (nom 14.5 psi)
1000-1500 RPM / 200 kPa (nom 30 psi)
2000 RPM / 250 kPa (nom 36 psi)
3000 RPM / 400 kPa (nom 60 psi)
 

·
Administrator
GUII ZD30DI Wgn
Joined
·
44,160 Posts
Im not sure how to test this. I imagine by going to a mechanic with a known working mechanical oil pressure gauge??
Tricky if you don't have access to gauges, or another sender.
 
21 - 32 of 32 Posts
Top