The Toyota Landcruiser Owners Club

[Norfolk & Clue]

Hi all

I am trying to find the oil pressure switch on my 1KZ TE engine. Struggling to find anything on line. On the passenger side of the engine I have found these three sensors. Any idea if any of them are the switch I am after. My dash only has an oil pressure light which can only light up red (clear bulb with red filter in front, so I assume not connected to the ECU?) I don’t have a pressure gauge.

Sensor / switch in red circle has two wires green and brown
Switch on blue circle just one yellow wire
Both behind the oil filter as you can see (A pig to get to!)
Switch in yellow circle at the front of the engine just below the OBD. One yellow wire.

[Google]

[Norfolk & Clue]

All just a quick update. The sensor in the blue circle is the oil pressure switch, the wire is actually yellow with a green stripe. I am fitting a remote oil pressure switch, pressure gauge and buzzer to indicate low oil pressure. I will post more info highlighting any problems I had.

[Tractionman]

Good idea.
Will you be teeing off from original sensor location with an adaptor, as most of the gauges I have looked at to do this are npt thread, and the lc is probably metric ?

[Norfolk & Clue]

I love working on my Land Cruiser but I can honestly say this was a really nasty experience. The threads didn’t match and everything was hard to get to. Kept on dropping adapters and having to rescue them from the depths of the engine (use steel plated adapters if possible so you can rescue them with a magnet).
I’ll post my work over the weekend it was a really unpleasant  job. Hopefully you can learn from my mistakes!

[Tractionman]

Although looking to do it on a 120, your thoughts, parts and experience of the whole thing are much appreciated and look forward to your write up.👍
As explained before, even doing the research was a pita, thread type, parts etc, as you have found in actually coming to do the job.
Well done on that !!
I know exactly what you mean with dropping bits due to limited access etc, and even if steel parts can be used (normally brass or even plastic) almost all areas make using a magnet next to useless, as it grabs all the wrong bits, especially with the bloody great aftermarket underbody protection I have. 🤔
Always willing to learn mate, even an old git like me !  Thanks.

[Norfolk & Clue]

You will need the following
Adapter hose
1/8 BSP male to male fitting one end tapered the other end parallel (or close to parallel) see info further down the page.
PTFE tape
24mm deep reach socket
12mm open ended spanner
Swear box
Lots of £1 coins for the above
A spare car to get stuff when it all goes wrong.
Shops that are open when you need them.
Spare skin for your knuckles.

It’s not actually that bad now that I have done it, but it was a real struggle and took about 6 hours and should have only been 1 hour max, most of my time was spent driving around Surrey trying to get the right adapters.
Sequence of works:
Remove air filter housing
Gunk and lightly jet wash area around and behind the oil filter
Remove oil filter and cover central spigot with a small poly bag and tie with an elastic band, this is the clean side of the filter, let’s keep it that way!
The release clip for the oil pressure switch  (below, the one in the blue circle) is on the underside. Squeeze the clip as hard as you can and wiggle whilst trying to pull. You need fingers like ET to perform this task.
Undo switch with a deep reach 24mm socket
Cut the wire to the switch connector at least 40mm from the plastic housing and solder on at least 500mm of  new wire and a 1500mm wire if you want to install an additional oil light or buzzer or both.
Strip, tin and solder the other end of the sensor wire (the portion that goes into the main loom) and join it to the new 500mm wire. (Cut the 500mm wire to a neat length before soldering).

Don’t try to fit the adapter to the block by hand, you will drop it and it will be hard to find,
Don’t try to attach it to a socket with an extension because you won’t be able to “feel” the thread, and you will almost definitely drop the whole assembly.
Both of the methods above will result in swearing, skinning your knuckles and losing small parts that will get hidden behind the starter motor, in the bash plate or on a small ledge that you didn’t know was there and can’t reach or even see.

The adapter I used is noted as a 1/8 BSPT (T for tapered) x 1/8 BSP
Fit the parallel end of the adapter to the hose with PTFE tape as a seal.
Then wrap the tapered end of the adapter in PTFE and guide the adapter in place via the hose that it is attached to.
Make sure you have got two or more turns by hand before GENTLY tightening with a 12mm spanner. Essentially you are using the hose as a flexi drive.
The instructions on the package said finger tight plus ¼ turn.  

Attach the original oil pressure switch to the other end of the hose (the T piece) with a PTFE seal.
Fit your new take off for the oil pressure gauge.
You will need to find a way of earthing the body of the original oil pressure switch. My method was a bit rubbish so I’m not going to publish it (unless you’re really struggling in which case message me).

Finally, I positioned the gauge under the bonnet to test it for fear of it going wrong and filling the inside of the car with hot oil. I’ll move it in a few weeks if there are no leaks.
I have also relocated the air filter housing towards the front of the engine bay so I can easily check for leaks. I may keep it this way because it gives good visual access to a congested area.

GETTING THE RIGHT ADAPTER

The original oil pressure switch has a tapered thread from about 9.55mm to 9.84mm
The kit I bought was 1/8 NTP the tapered part of the adapter was too big for the tapped hole in the engine block. This is part 2 as shown below.
Parts 1 &3 didn’t fit either. But finally I found a male to male 1/8 BSP adapter, I bought this from a trade counter that sells compressor parts. 1/8 BSP x 1/8  BSPT
PART 4 IS THE ONE YOU WANT! You will see the adaptor is tapered from 9.54-9.95. unfortunately, I can’t give any more info on this part as I bought so many and they all look similar, and I don’t know which receipt goes with which part.
I don’t think the thread pitch is too important because BSP and NPT seem very similar so over a few turns we are talking fractions of a mm. If you can get the tapered end to go in the block by hand you are obviously on the right track, IF NOT DON’T FORCE IT!!!
Ideally the end that attaches to the hose should be female conical the end that attaches to the engine block can be blunt or conical it doesn’t matter. I had to use a blunt end on the hose end because it is all I could find. It appears to have sealed well.  

[Tractionman]

👍Well done mate, great write up/list, thanks for sharing.👏

This has taken a lot of guesswork and the messing about you had, for the rest of us who want to do such a useful mod.👌
Some very good tips in there, I can now start sourcing parts to do the job when the weather improves. Thanks again.