Fingers

The water pump is sooooo inaccessible, and there's practically no room to mount the sender!!!

Can I install it in the plastic thermostat housing neck? Like drill/jbweld the fitting into it?

Thanks
-Ross

RETed

I would not recommend it.&nbsp They have a hard enough time trying to stay together without drilling holes into it...


-Ted

Fingers

LOL ... hmm... I guess i'm stuck with taking the water pump out then.

Has anyone done it with the water pump in the car, if so, do you have pics?

HAILERS

Well, why not try a different tack than the rest of the posts on this site. Set off in a new direction. See the approx 3/8ths water line that comes off the back of the water pump?? Goes to the BAC (man's best friend). Go to AUTOZONE. Look at where they keep the gauges. Look for Metric Adapters. Part number of the SUNPRO adapter is CP7556. It's name is OIL PRESSURE TEE ADAPTER KIT. Don't start shaking your head at me. You don't have to use it on oil pressure gauges. You can use it on any darn thing you wantta use it on. Now what this thing is, is brass tee fitting. It comes with a threaded pipe that can be screwed into any of the three ports on it. Cut that pipe in two, right down the middle. Now screw both halve into the tee. Cut that water hose at a predetermined point and install the brass tee with the now two pipes on the cut hose. Now screw your water temp sensor into the third port on the tee. WAllla. You now have a water temp sensor that can measure water temp prior to the thermostat.

By the way, for it to work, prior to the above steps, get your butane torch out and sweat a male or female terminal to the body of the tee. This will be the method of grounding the tee. Get a piece of wire and put a terminial on it that will match the male or female terminal that you just sweated on the tee. Attach the other end of the wire to a good ground of less than 0.5 ohms (measured with the battery positive terminal off and the negative terminal on the battery).

There. Now alls well, the suns shining, so put your windsurfer on the top of the car and go do something worthwhile......windsurfing.

Oh, if you dealer does not have the SUNPRO part listed...forget the above.

Cosmo Donk

I have some info on it in my Project Cosmo page. Also, if you are online you can throw me a line if you need anything.

Fingers

Hmmm... so I installed the sender in the plastic elbow with JB weld. It's unfortunate that I didnt see your post in time, Hailers Anyways, so far so good, but I do wish to move it to before the thermostat.

Thanks, pics and writeup coming soon.

HAILERS

It's fortunate you did not read my post first. It does not work. The temps read about ten degrees cooler than the temps from a sender mounted in the plastic/metal filler neck.

I think it's because of the direction of the flow of water. I thought it was from waterpump to bac to thermowax to rear housing. It must actually be from housing to thermowax to bac to waterpump. That's the only explanation for the temp drop that I see. I'll check it out sometime soon.

Filler neck is just fine. You still have a stock gauge and sender unit to tell you if the thermostat is blocked up. It'll peg is that is the case.

BlackRx7

Just get a metal thermostate housing off an 86-88 car it has a stock temp sender for the aux cooling fan to tell it to turn on, you can just remove the stock send and installed the aftermarket one, it even comes with the right size threads....

HAILERS

The exercise was to mount the sender in a place prior to the thermostat. The idea I came up with should work, just not where I placed it. If I place the sender in the hose that comes out of the rear housing and before it reaches the thermowax, then it will work and not show a ten degree difference from one mounted in the water filler neck.

I looked a the 91 fsm, cooling section, and sure enough the water flow is From the rear housing, to the thermowax, to the bac, to the back of the water pump. Results in a reduction of water temp of appox 10 degrees from the rear housing to the inlet on the back of the water pump. Someday I'll put it back there. I run a foot and a half long hose back there to make throttle body removal a piece of cake (vs that short ninty degree hose the factory installed).

Davidov

iTrader: (2)

How about getting an appropriate sized PVC (or even aluminum) pipe, cut a slice in the rear housing heater hose.

Then thread the PVC or aluminum, put the gauge in there, and stick a couple of hose clamps on either end of the "extension" if you will.

Good? Bad?

silverrotor

iTrader: (1)

Sure. But by doing that, you'd have to swap out the respective Water Pump Housing too.

JerryLH3

iTrader: (11)

That's essentially what HAILERS suggested. Place a T-fitting in the hose that comes right out of the rear housing, well before it gets to the thermowax.

Kenteth

Not to bring the thread back from the dead, but damn good info hailers! I've had a water temp gauge and sender sitting in the garage for about 6 or 7 weeks now. I have been waiting to figure out an easy way to install the sender, and I think you've provided it.

Since I have already removed the thermalwax and BAC, the rear engine plate output goes straight to the water pump housing. I'm going to reinstall the BAC and add the sender between the rearplate output and the BAC.

Thanks!

RETed

One minor problem...

If the coolant passages are clogged (which I've seen it happen), then you have "erroneous" readings off the sensor.



-Ted

Kenteth

So its just one coolant passage that leads to the rear plate outlet port? Is that one coolant track isolated from all the others in the system? Just curious. Do you think its still a decent way to go?

RETed

Yep, rear of water pump housing to...
BAC valve, to...
Throttle body, to...
Top of rear housing.

Any part of that coolant passage gets slightly clogged, the readings will be off.
It's a good compromise, but the sensor is most effective in the water pump housing.
Most temperature sensors are single wire, which means it grounds through the sensor itself.
If you got it hanging in a T in some rubber hose, it needs to be grounded with an extra wire.
Yeah, drilling the water pump housing is a pain in the ***, but this thing is important, right?
Might as well do the job right the first time and get the most accurate readings you can...


-Ted

Kenteth

Yeah I suppose so.

I had a question, I was thinking about. For all the guys who cap that rear-plate port, and WP port... doesn't that passange never get coolant flow? I always figured it wasn't isolated from the rest of the system, but if it is-- it means capped it never gets flow?

Wanked_FC

iTrader: (1)

I heard it wasnt good to block that passage, I have my thermalwax and bac gone. I just routed the coolant from the plate to the pump w/ a 90 degree heaterhose from autozone.

HAILERS

I'm of the opinion that the flow of water is FROM the rear housing nipple TO the throttle body, TO the bac, TO the back of the water pump. Yeah.

That said.....I never tried to install one right after the nipple on the rear housing, but someday, someday....

Another BAD place I tried was the water hose that feeds the heater core. I installed a temp sender in that hose approx two/three inches from the outlet on the block/housing (you know, the one below the oil filter/oil sender). Even though it was just a couple of inches away from the block, if the heater was not turned on the reading was always twenty plus degrees to low. Had to turn the heater on to get a accurate reading.

Presently one car has the sender in a piece of pipe in the outlet hose from the filler neck(requires soldering a ground tab on the pipe the sender is in) and the other car has its in place of the fan temp sensor located in the filler neck just after the thermostat (not good til the thermostat opens).

SOmeday, someday, I'll drill and tap the water pump housing.

RETed

No, if you look at rear iron and the water pump housing, it's just an extra fitting.
It does not dead-end at those fittings, and we cap them off on all our race cars to eliminate one more failure.


-Ted

RETed

You are probably right.
It's just automatic I think front-to-back.


-Ted

Kenteth

Welp, I did an install in that location. I figured I had nothing to lose as I didn't feel confident enough to be drilling the water pump housing.

I later ran the wire and ran wire to ground the brass attatchment. I took it for a test. At idle I was running 190, when I got on it, it would rise to about 205, then come back down to 190. Does this seem low for the rotary?

Kenteth

Ok I've been driving with the sensor installed there for just over a week or so. Idle temepratures are around 180, and driving temperatures are slightly higher aroudn 190. When I get on it I saw the temp rise to right around 200.

Do all those temps sound normal or low?

RETed

Those numbers are normal.
http://fc3spro.com/TECH/MODS/EL/GAUGES/wtemp.htm


-Ted

WAYNE88N/A

Since any different mounting location along the coolant flow paths are going to give you different readings, as alluded to above, there is no "normal" temp. Granted, we usually consider 180-190 normal, but that just happens to be right at the location of the thermostat, after the coolant has passed the hot combustion areas of the housings and is on its way back out of the engine. If we could somehow get our OEM gauges to read specific numbers from the point of the OEM sender location, the temps would be much cooler than at the t-stat housing, because the flow hasn't picked up the rotor housings' combustion area heat yet. In fact, if I'm interpreting this crappy picture of coolant flow paths in the FSM correctly, the coolant has just entered the engine and passed the intake & early compression stage portions of the housings, so it will be closer to radiator temps than actual thermostat temps. So, 140*F could actually be a "normal" temp at our OEM sender locations...

It really doesn't matter where it's mounted, as long as you have a good understanding of what the temps should be at that particular location. Anything wrong with the coolant system will show up as exaggerated temps, no matter what location the sensor's at, except maybe at the heater circuit mentioned earlier...Heck, even one mounted at the drain valve location at the bottom of the rad is going to give you an idea of how she's cooling once the t-stat pops...