Oil pressure sender, where, on/off or analog, thread size.

[Pascal]

Hello,

I have a Land Rover with a LD28 engine. When the engine was built in all electric wiring that was not essential for the running of the car was stripped:
e.g. no thermal sensors connected (I found those), even the glowing timer was taken away and is replaced by a simple switch (I think I will install one later). I found most information in the FSM.

However I could not find where the oil pressure sensor is, if there is one.
If yes, is it an on/off switch for a light in the dashboard, or is it an analog sensor for a meter (or both)?

If there is none or mine is broken where could I install one? and using which thread?

Pascal

[asavage]

If yes, is it an on/off switch for a light in the dashboard, or is it an analog sensor for a meter (or both)?

In the US, I have not seen a Maxima (the Bluebird/910 in other parts of the world) with an analog (or even digital) oil pressure gauge. The gasser version of the Maxima had the analog OP gauge fitted as standard, and the digital dash was optional, but I do not think that the digital dash was an option for the diesel version.

Nonetheless, NAPA (US auto parts chain) lists a gauge sending unit for the LD28, though I've never seen nor heard of one fitted:

NAPA Echlin OP6081, US$64
Attributes:
Thread Size:1/8" x 28 thread
Pressure Rating:90 PSI system
Type of Packaging:Box
Features & Benefits:Gauge Type


The LD28s I own and the ones I've seen have all been fitted with a standard snap switch for the oil pressure. It is impossible to take a photo of it, as it is located under many lines. If you locate the oil level dipstick and follow it down to where it meets the block, then move toward the rear and look just above where the engine mounting bracket mates to the engine block, you should see a plug, or a fitting with a plug. Due to the IP injector lines, it is not very accessible from the side, and various coolant hoses run above it.

As fitted to the Maxima, there is a brass adapter elbow at the block (perhaps 75°), and the switch threads into it. The orientation of the installed switch is nearly straight up (ie wire terminal is facing upj).

Based on NAPA's description, the thread is 1/8" x 28 TPI, which is British Standard Pipe thread (BSP), not SAE NPT whcih is 1/8" x 27 TPI.

This is what the OP snap switches I've seen on the LD28 look like:

NAPA OP6116SB, US$7


Hope this helps.

[davehoos]

oil gauge for a LD28 R30 skyline/C31 laurel will have 2 wires.1 is oil light the other is gauge.both earth to engine ground.later engines have the same plug directly in the end of sender.

australian built cars use VDO sender unitpil conector is light switch spade is the gauge..many have different calibration.same can apply to other nissan products world wide.

the Isuzu engines fitted to landrover here had a 2 wire oil light switch insulated from the body,conected in series with the reverse light switch,this same idea is often used to prevent the engine running without oil pressure.

[Pascal]

If you locate the oil level dipstick and follow it down to where it meets the block, then move toward the rear and look just above where the engine mounting bracket mates to the engine block, you should see a plug, or a fitting with a plug. Due to the IP injector lines, it is not very accessible from the side, and various coolant hoses run above it.

On the picture "I don't know how to upload so I sent it to you Al" I've indicated those 3 reference points. I am a bit confused because you say towards the rear of the engine from the oil level dipstick on.

Can you maybe indicate on the picture where I should look.

Thank you

[goglio704]

Pascal,

While I haven't seen your picture, it would be nearly impossible to take a picture on one of mine because of the obstructions. If you look between the oil dipstick and the oil cooler/filter mounting, you should see a raised boss in the casting. That is where my oil sender is mounted. Hope this helps.

[asavage]

This is Pascal's picture:



I can see why you're confused: the US-spec LD28 as fitted to the Maxima has the oil dipstick positioned forward of the motor mount, and not back near the starter as shown in your diagram.

[Pascal]

Hey I found it!! Thanks

At the location where you point there is a bolt sitting, So there I will install an oil pressure sender with the thread is 1/8" x 28 TPI. I hope that the bolt sitting there has the correct thread and has not damaged the thread of the engine.

I will try to find a combined sender like Davehoos mentioned.
I did not fully understand :

australian built cars use VDO sender unitpil conector is light switch spade is the gauge

and

in series with the reverse light switch

do you mean the reverse light attached to the gearbox for driving backwards? When there is no pressure the reverse light does not light up, and then?
How does this prevent the engine running without oil?

[asavage]

One potential problem with a combined sender is that the sender's resistance range (for the gauge) must match the gauge. I do not know how to determine which gauge will match with a combined sender chosen at random from a parts bin.

The usual workaround for that problem is to plumb a tee, and use a separate switch (for a light, or for the IP shutdown system as used by the Nissan SD22 in model 720 lorries) and a separate gauge sender. In this manner, you can have both a switch for an indicating lamp or whatever, and also a sender that matches the gauge you choose to fit your particular instrument panel.

[davehoos]

How does this prevent the engine running without oil?
on the land rover it wont it just to stop the reverse light working without the engine running.militara use.but on landcruisers isuzu etc it shuts off the engine the landrover 3.9 is a truck engine and can have 3 oil pressure switches.one conected to the stop motor.

i mention the VDO gauge used in 910/R31 as in australia VDO cockpit gauges are used in the landrover dash they fit in to the standard fittings or in the senter dash panel..the nissan uses a combination VDO switch that rarely leaks oil.the resistance settings are .low 10 ohms-high 180 ohms.

nissan japan sender[S13/R31/D21-all mid 80,s] engine stopped more than 73ohms-idle less than 50 ohms.so its reversed in scale.

the photo of the napa gauge looks like the light only sender on my 910 LD20T,and a american made gauge sender i got recently for my falcon.[motocraft label]

[goglio704]

Pascal,

Would you mind taking a look at this thread and sharing any info you have on what transmission your vehicle uses and how it attaches to the LD28? Thanks.

[kassim503]

If I were you I would also rig up some kind of oil pressure on/off switch to a buzzer if you lose oil pressure, beats the light and the gauge. Or put a T fitting in and wire the gauge and buzzer in, losing oil pressure is no fun, but losing it and continuing to drive is even less fun

[asavage]

If I were you I would also rig up some kind of oil pressure on/off switch to a buzzer if you lose oil pressure, beats the light and the gauge.

I've done the buzzer thing, and it's just annoying. I prefer the light, but only if it's where it can catch my attention. I won't hear the buzzer over the radio.

When I put low oil pressure buzzes on our industrial equipment years ago, all the operators tore them out within a month. Annoying, yes. The buzzer comes on every time you start the engine.

[kassim503]

Once upon a time, I drove a School Bus for bread, had a buzzer and on those cold mornings where you gotta wait for the glow plugs and intake heater to heat up, that buzzer really did kill me, yeah, id probably install a light that you'd notice quickly, I definitely take that whole buzzer thing back.