18R-C Oil Pressure Switch

[Raforty]

I have re-built, with a friend's help, a stock 18R-C engine in a 1979 Celica RA40. New seals, rings, bearings, nicely painted, etc. However - when it comes to the oil pressure gauge sender and oil pressure switch sender...mystery abounds. Just where do these gadgets go?

The drum-shaped gauge sender found a home with an appropriately sized and threaded hole in the block.

The obvious place where the plug-shaped pressure switch sender goes is a threaded hole too large for it. I can only think that a bolt has blocked the correct place, but haven't found it yet. (The oil pressure switch sender is the same as extracted from the car originally.)

My Haynes manual is not detailed enough to show, and my local wreckers yard has no intact 18R engined car. Googling doesn't help, either.

Any detailed diagrams of the 18R block out there?

[Norbie]

I seem to recall two threaded holes towards the front of the block on the driver side, one of these has the oil pressure switch and the other is blanked off.

Your other option is to use a T-piece to attach both senders to the same hole.

[floppy]

Hey,

Check this post out.

Exploded diagrams of the 18r courtesy of river.

http://www.toymods.net/forums/showth...t=18r+diagrams

Dave

[Raforty]

Thanks, Toyota friends.

Alas! The engine diagrams thread was detailed, but the side with the switches was not well covered.

The two switches might both emerge from two sides of one small flange, but would then physically foul each other.

I may have to screw a matching bolt into any threaded holes left over, so that no oil shoots out when I turn on the engine, and try a process of elimination afterwards.

Previously, I installed a simple device that made the carburettor more efficient, boosting fuel economy from 21-22 mpg to 29 mpg on this stock RA40 Liftback. If there's any interest, I'll start a new thread on this.

Regards

Raforty

[floppy]

Hey,

With that little flange, I think I know the one you are talking about, I added an oil pressure guage to my 18R and I just put a T-piece into that main one that the oil light sender goes into.

Their is another opening in the flange that had a small bung in mine, but as you said depending on the size of the senders they would foul each other.

There are no other threaded areas that have oil access that I know of.

On the block in this picture, the bottom right shows the oil guage threaded area with a little bung in. The rest of the holes are used which you can see in the next pic.

[IMG]"http://picasaweb.google.com/floppydj/18RG/photo#5154212690789497298"[/IMG]
http://picasaweb.google.com/floppydj...12690789497298

This is for an 18RG, so the oil sender is in the oil filter housing, in the photo I hadn't yet put the T-piece in. (I am running the guage, RG sender and another sender to a secondary light)
http://picasaweb.google.com/floppydj...13914855176674

Anyway hope the pics help, I am by no means an expert on these things, I've just finished a block and had some pics handy

Dave

[Raforty]

Thanks, Dave.

That lower corner block extension in your close-up is where the sender(s) go...I think. I took the bolt out and screwed in a sender (like the one in the picture) successfully where the bolt was. I then tried the drum-shaped sender on the horizontal hole, and it fouled on the plug-type sender in the diagonal location. Both of these holes access the oil galleries.

(I don't have an oil filter housing with a plug hole like yours.)

It may be that one sender (the drum shaped one?) may serve the needs of both an oil pressure switch and a gauge sender, and that once I start the engine, I won't have problems...I can't be sure, since a friend and I parted out another car and had bits left over from a third. Maybe I have one too many senders and the car only uses one?

Regards

Raforty

[floppy]

Thanks, Dave.

That lower corner block extension in your close-up is where the sender(s) go...I think. I took the bolt out and screwed in a sender (like the one in the picture) successfully where the bolt was. I then tried the drum-shaped sender on the horizontal hole, and it fouled on the plug-type sender in the diagonal location. Both of these holes access the oil galleries.

(I don't have an oil filter housing with a plug hole like yours.)

Yeah I think they came on the 18RG versions.

It may be that one sender (the drum shaped one?) may serve the needs of both an oil pressure switch and a gauge sender, and that once I start the engine, I won't have problems...I can't be sure, since a friend and I parted out another car and had bits left over from a third. Maybe I have one too many senders and the car only uses one?

Regards

Raforty

The 18R I just took out of the RA23 only had the 1 sender. I am not sure if it will do both. I think they are different though, the one for the light works differently to the sender for a guage as far as I knew. Hopefully someone else can chime in here and let us know

Dave

[mike1980ra40]

The 18R I just took out of the RA23 only had the 1 sender. I am not sure if it will do
both. I think they are different though, the one for the light works differently to the sender for a
gauge as far as I knew. Hopefully someone else can chime in here and let us know

Hi there,
as far as i know oil pressure sender works on resistance (hatchbacks). higher pressure higher
resistance higher reading on gauge (i think)

my RG doesn't have that hole at the filter for the switch, interested in knowing where i could
find one for this ---> http://www.toymods.net/forums/showthread.php?t=7462

cheers.