Water Temp guage - First Generation Forum

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Water Temp guage
Thursday, July 02, 2015 10:49 AM
Hey guys, please be patient and read through this as I need a little help here. I have a couple of dumb questions, too.
I've noticed lately that when I drive my wagon in stop and go city traffic that I lose a little bit of antifreeze that ends up on the motor/ tranny mount (not even an ounce) next to the thermostat housing. This got me thinking. I have NEVER seen my cooling fan running and I usually drive the car primarily only on my five mile drive back and forth to work. If I put the AC on, the fan doesn't come on, but the freon is gone and the compressor doesn't engage, so I'm not sure if the fan would go on anyway. I have left the car running for a half an hour in my driveway and still, the fan doesn't go on. It doesn't appear that I have ever overheated the car, at least it has never acted like it's been overheated. I replaced the two sensors on the thermostat housing with new ones (the one with a yellow and black wires with two pins and the other with two green wires going into a one blade terminal) a couple of years ago along with a new 192 degree thermostat at the same time. I jumped the fan relay and the fan engaged. I also checked the fusible link and ground with a multimeter and both have good continuity. The car has an idiot light only that doesn't come on when the ignition is turned on like the oil and amp light do. I pulled the one blade terminal plug off and nothing happened (no fan, no idiot light), I pulled the two pin plug and couldn't start the car (it kind of flooded), so my guess is that the black/ yellow wired sensor goes to the ICM.
So the dual green wired sensor is for the idiot light? I got on Rock auto and found the two sensors on the stat housing, along with a third sensor which was called a "fan switch" which has one screw-like terminal which I cannot find anywhere on the car.
So here are my dumb questions: Does anyone know for sure what the two sensors on my stat housing are for and if I put a mechanical temp gauge on the car, which one of the sensors do I delete?
My guess is it would be the one with the two green wires, but I'm not sure.
I had a GM dealer give me a parts breakdown for my VIN, but it shows at least a half a dozen sensors possibly being there and the descriptions of these sensors are vague at best.
Here's the gauge I am going with:

I plan on replacing the sensors again, stat and fan relay just to be safe, but I'd like to only replace the sensor I need.
I wonder if I am going to end up having to install a manual fan switch... I hope not, but I will if I have to...
Maybe my engine is just not getting warm enough to turn on the fan and nothing is wrong, but I'm not willing to cook the engine in order to find that out !!!
Any input would be greatly appreciated !



~ Mike ~



Re: Water Temp guage
Thursday, July 02, 2015 12:14 PM
mike you dont have to delete any sensor. go to the hardware store and get some brass fittings to make a tee, the tee srews into the housing and the sensor and gauge screw into the two ends of the tee. this way you have both .ive done this on all my cars that ihave added a gauge. you can do this if your adding an oil pressure gauge too. use teflon tape or pipe sealant on all the threads. i would also go with a lower temp themostat hook up the gauge first, run the car and see where your at then go from there. take one of the sensors and the gauge to the store to make sure you get the right threads. as far as the fan goes mine takes an awfully long time for it to go on. like 220degrees i wouldnt replace anything untill you find out what your car is actually running at. take it slow, no need too waste money
Re: Water Temp guage
Thursday, July 02, 2015 1:07 PM
That's a great idea, John!
It would have to be a pretty big tee, though - the probe for the temp gauge is about an inch and a half long!
Might have to get an extension for the one side of the tee.






~ Mike ~


Re: Water Temp guage
Thursday, July 02, 2015 1:15 PM
On the right side of the car, near the front of the wheel well, there's a large plug (like an what you put into an electric socket in your house). If you unplug this, you should be able to run your fan by sliding your HVAC switch to AC. My fan doesn't seem to go on by itself either, and after playing hit and miss with a few things, this is the way I've decided to go.
Re: Water Temp guage
Thursday, July 02, 2015 4:49 PM
Go to Home Depot , get some Glavenized pipe the size close to your radiator hose diameter, drill and tap a hole the size of your sensor and cut your hose and clamp it between. Or go to Summit or Jegs annd buy one allready done.

http://www.summitracing.com/int/search/part-type/temperature-sender-fittings?N=4294947274&SortBy=BestKeywordMatch&SortOrder=Ascending&keyword=radiator%20hose%20%20adapter

A piece of exhaust tubing may work also with a bung welded on.

Doug in P.R.


92 Pontiac Sunbird LE, 2.0, AT, Red / Black with Grey 143 K miles.Slowly getting back to a halfway decent car............in Salinas, Puerto Rico!




Re: Water Temp guage
Thursday, July 02, 2015 5:45 PM
If you get real motivated, you can get or make a double fitting one and run your fan ground to an 80 Citation V6 fan thermo switch that completes the circut when it gets hot. ( you would have to run a ground wirw from the hose adaper to the block though)

http://www.autozone.com/cooling-heating-and-climate-control/cooling-fan-switch-radiator/duralast-cooling-fan-switch-radiator/chevrolet/citation/1980/6-cylinders-7-2-8l-2bl-ohv/2642_0_0 /


http://www.partsgeek.com/catalog/1980/chevrolet/citation/cooling_system/engine_cooling_fan_switch_connector.h

Doug in P.R.


92 Pontiac Sunbird LE, 2.0, AT, Red / Black with Grey 143 K miles.Slowly getting back to a halfway decent car............in Salinas, Puerto Rico!




Re: Water Temp guage
Thursday, July 02, 2015 5:58 PM
80 Citation 2.8 V6
Description System Mounted Cooling Fan Temperature Switch
Description Mounted on Engine Block. 9/16" Probe.
Off - 220 degrees
On - 230 degrees


Doug in P.R.


92 Pontiac Sunbird LE, 2.0, AT, Red / Black with Grey 143 K miles.Slowly getting back to a halfway decent car............in Salinas, Puerto Rico!




Re: Water Temp guage
Thursday, July 02, 2015 8:43 PM
MIke I have done some mild research for the wiring.I will say 220 is when the fan will engage,and since you checked the item's said never mind those.Now I can 100% say the yellow/black is your Low Coolant idiot light.The double Green is the actual wiring going to the ecm for the engine temp(therefore engaging the fan once the car goes above said temp) and or if the ac cycled needed to kick the fan on a high idle circuit.If you want the technical side is for the coolant temp sender is resistance is 1365ohms at 100*(38*c) 55 ohms at 260*(127* c) Not that any of this matter's.I would go brass on T eeing up a set up,Plus I hate Teflon tape and use Permatex high temp thread sealant (in a white tube) sold at most auto store's.I recommend this 100% as I have only used this for years on end on any sending unit and perfectly safe and sooooooo much easier to use and seals,oil,coolant,trans, and even gear oil.A small dab and rotate the sender in and done! I will say napa sells the bigger tube of the permatex as this last a long time.I will work on sourcing your request as in my parts chest 0 are in my containers.



Re: Water Temp guage
Sunday, July 19, 2015 8:17 AM
Well, I went out and purchased a tee, and bought a couple of new senders and even a fan relay, along with new heater hoses a new bypass hose, upper and lower rad hoses, and a 180 degree thermostat to replace the 195 degree stat.
Dumped the coolant, got everything switched over and decided to read the instructions on installing the new temp gauge.
Here's where it gets screwed up: The instructions say that you cannot use a tee when you have cars with sensors and ECMs! It says the sender and the sensors have to be in the flow of coolant or they won't accurately measure the car's true coolant temperature because there is not enough coolant flow in a closed tee (which after thinking about it, I would agree with..), SO, I bagged installing the temp gauge and tachometer like I planned to do and now have to either go out and get a 3/8 pipe thread tap and drill and tap my thermostat housing, or get an already tapped thermostat housing water outlet that come on some of our Cavaliers:

I'll put the temp gauge sender in that fitting. I know if I put the gauge sender above the thermostat, the gauge won't be super accurate until the thermostat opens up, but at least I can monitor the temps after the engine is warmed up. Not sure which way I am going to go. There is a spot on the stat housing where I can drill and tap it, so I'm going to have to think about it a little bit...





~ Mike ~


Re: Water Temp guage
Sunday, July 19, 2015 8:28 AM
Oh, I forgot to mention that after I buttoned everything up and fired up the car to get the air pockets aout of the cooling system, the fan came on, the car went into high idle and the check engine light came on !
Turns out, one of the new sensors I got from RockAuto was bad... (the one with the yellow and black wires)
Fortunately, I had replaced that sensor only a couple years ago, so I put it back on and all is good now !




~ Mike ~


Re: Water Temp guage
Sunday, July 19, 2015 10:47 PM
Umm too tired to think on that stuff at the moment.Interesting and When I am driving for hours like Monday I will ponder this as well.




Re: Water Temp guage
Monday, July 20, 2015 7:38 AM
Another thing to report from my work on my Wagon:
I drove it into work this morning and noticed the car started easier and now the idle is a bit lower, which turned out to be a really good thing! The car always seemed to me to be about 150/200 RPMs higher at idle to me than it should be, in fact, the car's idle seemed to make the torque converter lock in and out at red lights and that would cause an annoying vibration at idle when the car was stopped. I screwed around with the IAC valve, a ton of times, even bought and installed a new one, but I could never get the idle right..
Now the idle is lower and the car sits there idling while stopped as smooth as silk !
I'm not sure exactly what I changed on Saturday that fixed the idle issue (my guess would be the single-bladed temp sensor), but I'm not going to complain about it ! I imagine that my brakes should ear a little better too!!!
VERY happy with the results !






~ Mike ~


Re: Water Temp guage
Monday, July 20, 2015 9:32 AM
Just FYI Mike the throttle bodies have a plug you can remove and behind that is an idle adjustment screw.

I've toyed with it on the Sunbird but never had a need to on the wagon - completely forgot about that till now , sorry.

I also have had a few occasions over the many years with my Wagon where the idle shot up on me and was annoying as hell - car wanted to idle at about 35MPH and I had to used the brake a lot around town. Mysteriously after a few days it would back down to normal before I'd get a chance to tinker with it. Nowadays I just let it have it's "spell" when It decides to act up since I know it will settle down on its own.



.



Re: Water Temp guage
Monday, July 20, 2015 1:13 PM
I have been driving my Wagon for so long with a slightly higher idle that it seems odd to me now, Orlen.
I knew about the screw, but felt if I dropped the idle too low that the car wold possibly stall out..
I have to admit that I am VERY HAPPY that changing the sensor helped so much !





~ Mike ~


Re: Water Temp guage
Monday, September 07, 2015 6:05 PM
Ok, finally got some idle time this weekend, so I figured I'd finally install the temp gauge on the wagon.
Bought a dual pod gauge holder (snagged a digital tach on Ebay a couple years ago, so I figured this would be a good time to install it!), bought the thermostat outlet housing with the threads already in it for the sensor from RockAuto and decided to install the gauge pod where the ashtray originally was. I don't smoke and don't allow smoking in my Wagon, so it wasn't being used anyway. Had to drill a HUGE hole through the firewall to allow passage of the huge pipe thread fitting on the sensor to go through it, used the wiring for the ash tray light for the back light of the temp gauge.
I also decided to ditch the original 195 degree thermostat and replaced it with a 180 degree Stant SuperStat:

Took some old advice from Orlen from a couple of years ago and spliced the tach pulse wire to the white wire from the distributor, the power lead to an ignition power prong on the fuse panel ground it on the dashboard frame and, VIOLA ! It all works great !

Drove the car around up and down a couple of hills and the car runs around 190 to 195 degrees during normal driving and tops out about 205 degrees when pulling the long and steep hill to my house..
All in all, not a bad bit of work for the day !


~ Mike ~


Re: Water Temp guage
Thursday, November 19, 2015 5:31 PM
I think that a car that starts the fans at 230f is nuts. The factory thought that
if there was a certain amount of coolant in the system that it would solve the
overheating problem. This is one of the reasons why the J bodies are referred to
as a crappy car with the low resale value to match.
What's my gripe:
This stock car that has a few years on the coolant will sometimes overheat in
summer conditions. That's why they are so rare these days. Blown head gasket
issues. If a fan comes on way after it passes the boiling, it's really not protecting the
owner or the engine.
I guess after all this bitching you're expecting the solution?
ok
How did I fix GM's awful debauchery?

After so many years gunk will coat the inside of the radiator rendering it basically
useless. I make sure I replace this asap, with my choice being an aluminum radiator
bought inexpensively +/- $90 on Ebay. And no cleaning an ancient radiator is really not good enough.

The real trick to solve the overheating problem is two fold.
Replacing the fan sensor with another factory one is senseless, and yes they really
turn on at the 230-235f range. I replace one with a low temperature range sensor ;
the common ones are often 170-185 or 185-200f range. The warmer one may be good
in winter if it is really cold but it will work fine either way. I use the 170-185f sensor.
I replace the thermostat with a 180f one. It does the trick. Everything bought on Ebay!!
If you combine the new radiator + lower degree sensor + 180f thermostat= 185f that goes
down to 170f when the fan cools it down. You may also need a new fan motor as well
with these older model cars.
I have also found more tricks with these models, questions are always welcome.
Re: Water Temp guage
Friday, November 20, 2015 10:40 AM
With a 50/50 antifreeze and water mixture in a system under 15lbs pressure, the boiling point is close to 265 degrees F.
Re: Water Temp guage
Friday, November 20, 2015 7:40 PM
Owning my 85 for 17 years I have not once had a temperature issue period.Still run the oem spec'd thermostat and original radiator but,updated all the cooling hoses,and general maintenance and done.I run a stronger mix of antifreeze for a improved cooling protection point.Honestly just keeping the cooling system maintained and the engine in general everything works as it was designed in my opinion FINE!Not to discount on some say v6 models are more prone to cooling issue's I find very seldom do the 4cylinder engine's have cooling problems or break downs in my recall over all.Every car while built to be the same in general they all have there own personalities with or with out particulars.



Re: Water Temp guage
Saturday, November 21, 2015 1:50 PM
I went with a 180 stat and now the car rarely gets over 200 degrees on the guage - granted, I rarely drive the car for more than 15-20 miles at a time.
I actually think that I may go back to the 192 degree stat because with the lower temp stat, my heater doesn't seem to work as well...
I agree with Ron. Regular maintenance is key to a properly running vehicle... AND, ALWAYS run a 50/50 mixture of antifreeze/ water, You are playing with fire if you play around with your dilution rate, believe me, I've run a diesel engine machine shop for over 20 years now and I've seen what happens if your run the wrong antifreeze mixture in your engine..






~ Mike ~


Re: Water Temp guage
Friday, January 08, 2016 6:42 PM
Just reading through this thread as id love to install a temp gauge in my wagon. Let me ask a stupid question if the sensor with green wires is what the ECM is reading for temp could you piggyback those wires to an electric gauge and accurately monitor it?
Re: Water Temp guage
Tuesday, January 19, 2016 1:43 PM
William Dugay wrote:

Just reading through this thread as id love to install a temp gauge in my wagon. Let me ask a stupid question if the sensor with green wires is what the ECM is reading for temp could you piggyback those wires to an electric gauge and accurately monitor it?




I'm not sure is that is entirely feasible - the gauge would have to be properly calibrated to the sensor and I don't know what you could do to assure that to be the case.








~ Mike ~



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