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Technical => Engine Tech => Topic started by: jpc647 on April 04, 2009, 06:31:04 PM

Title: Wacky Temperature Gauge
Post by: jpc647 on April 04, 2009, 06:31:04 PM
Well I was having problems with my temperature gauge a while back, and after replacing the t-stat, and the sending unit, its still a little wacky. With the heater off the gauge seems to read normal, about half when its been running, maybe a tad bit more.

When I turn the heater on the gauge goes up around 3/4. I'm wondering if anyone has heard of this before, it it happens to any of you guys, and what might cause this.
Title: Wacky Temperature Gauge
Post by: Cougar5.0 on April 04, 2009, 06:59:09 PM
Air in the system?
Title: Wacky Temperature Gauge
Post by: massCougarxr7 on April 04, 2009, 07:33:46 PM
lol.... sorry,... ive been having the same issuie,... and all i can come up with is maybe the fan clutch is burning out, cause im betting you dont turn on the heat til the car is warm, so everything seems  ok, then when the heat goes on, it seems fine but then gets a little hotter and hotter till it stays around the R and M, and if you get on it for a little, or get aggressive it goes Past the M..........if the clutch is bad, it wont pull enough air through the radiator....
 
 thats how mine is anyway, i havent gotten the clutch until i go get my injectors and comp........
 just me two cents anyway!!!!!
Title: Wacky Temperature Gauge
Post by: jpc647 on April 04, 2009, 08:14:39 PM
Anyone know how to test a fan clutch? Is it still if the car is cold, and you try to turn the fan it should spin freely?
Title: Wacky Temperature Gauge
Post by: jpc647 on April 04, 2009, 08:15:16 PM
Quote from: Cougar5.0;265830
Air in the system?


I checked that too. That was what my father suggested as well.
Title: Wacky Temperature Gauge
Post by: softtouch on April 04, 2009, 10:37:03 PM
When you say "turn the heat on" do you mean the blower?
How about if you turn the blower on with out the heat on? does that make the temp gauge go up?
Are the fuel and oil pressure gauges also affected?
What I am building up to is a possible flakey IVR.
Title: Wacky Temperature Gauge
Post by: jcassity on April 05, 2009, 03:32:35 AM
Quote from: softtouch;265873
When you say "turn the heat on" do you mean the blower?
How about if you turn the blower on with out the heat on? does that make the temp gauge go up?
Are the fuel and oil pressure gauges also affected?
What I am building up to is a possible flakey IVR.


x2 and
Does the increase happen instantly or gradually?

Fan clutch bone cold> you should not be able to spin it by hand more than a half turn.

next time you park the car, pop the hood and watch the fan as you shut down. observe the qty of rotations, try to guess either rotations or spins.  The fan should stop within a second or two of shutdown.  just count it 1 one thousand, 2 one thousand.

To me, it would run hotter with the heat off.  Running the blower cools the core and helps cool the coolant.  your getting the opposite response, tells me im probably lookin for electrical issues.
Too much current draw perhaps.
Title: Wacky Temperature Gauge
Post by: jpc647 on April 05, 2009, 05:19:21 AM
Quote from: softtouch;265873
When you say "turn the heat on" do you mean the blower?
How about if you turn the blower on with out the heat on? does that make the temp gauge go up?
Are the fuel and oil pressure gauges also affected?
What I am building up to is a possible flakey IVR.


The fuel gauge does not move during this, not enough to notice anyway. Its a base cluster so no oil pressure gauge, just a light.
Title: Wacky Temperature Gauge
Post by: jpc647 on April 05, 2009, 05:21:12 AM
Quote from: jcassity;265897
x2 and
Does the increase happen instantly or gradually?


To me, it would run hotter with the heat off.  Running the blower cools the core and helps cool the coolant.  your getting the opposite response, tells me im probably lookin for electrical issues.
Too much current draw perhaps.


It happens within 15 seconds or so. I would have though the temperature gauge would decrease when the heat/blower are on too, as you are taking hear away from the motor.

I'll check the fan clutch today and let you know.
Title: Wacky Temperature Gauge
Post by: jpc647 on April 25, 2009, 09:06:27 PM
jcassity,

when you say you shouldn't be able to spin it more than half a turn by hand, do you mean like spinning it and letting it off and allowing the fan to free wheel, or by keeping your hand on it all the time?
Title: Wacky Temperature Gauge
Post by: Beau on April 26, 2009, 12:17:38 AM
When it's cold, ideally, it should be hard to rotate, when it's warm, the viscous materiel inside the clutch allows it to turn a little more freely.

If the gauge goes higher than normal right after you first start up after a long time sitting, I'd suspect an electrical problem first.
Stock gauges are kinda vague anyway, if you can afford it, buy a small coolant temp gauge, and install it and see how warm it's really getting...odds are your temp gauge might be slightly off.
Title: Wacky Temperature Gauge
Post by: V8Demon on April 26, 2009, 12:33:08 AM
Quote from: jpc647;269112
jcassity,

when you say you shouldn't be able to spin it more than half a turn by hand, do you mean like spinning it and letting it off and allowing the fan to free wheel, or by keeping your hand on it all the time?


He means when it free-wheels.  If it just keeps going, it's done.  Replace the clutch.
Title: Wacky Temperature Gauge
Post by: jcassity on April 26, 2009, 11:18:11 AM
spin it and let it free wheel.

just spin and let go.

This would be with a bone cold motor though.

with a hot motor,, dono, probably the same result.

temp fix---
remove one of the bolts that attaches the clutch to the fan blades.
install a longer bolt
install until you feel resistance then just keep turning until you feel something kinda break.

you just put the guts insided the clutch in a bind with the longer bolt,,,thus making the fan solid.

enjoy your new noise maker,, sounds good with a solid fan
Title: Wacky Temperature Gauge
Post by: jpc647 on January 04, 2011, 07:10:24 PM
Well this issue came back. Now I know it only happens when it is cold out. I took the radiator cap off and put my temperature measuring device into the coolant it read 130 degrees.  I pushed it further down and got readings as low as 90 degrees.  I put it right near the temperature sending unit and it was reading around 200, this is right on the intake manifold. So I think it's impossible the car would be running hot, or hotter than it should be. I spun the fan clutch and it doesn't spin very long when cold. I didn't seem to notice a difference between warm and cold though. The radiator does flow, it is old, but I can see it flow freely. It is fine in the warm weather, so it must flow. Would temperature affect a fan clutch?

I have a thermometer unit with a metal probe that displays a digital readout of the temperature. I tested it, I hold it up outside, and it read like 32 yesterday and that is what the thermometer on the outside of the house read 33. I put the over on to 200 yesterday too and put a pan of water in there, i took it out after like 20 mins and my thermometer read 202. So it's pretty accurate.

I figured with all of the new people around here lately, someone might have an idea.
Title: Wacky Temperature Gauge
Post by: 20thanniver-ls on January 04, 2011, 07:27:51 PM
Quote from: jpc647;348378
Would temperature affect a fan clutch?



Yep. As the engine temp rises the coil allows silicone fluid to enter the clutch and when it fills the grooves in the clutch body and plate  it engages  the clutch.
Title: Wacky Temperature Gauge
Post by: Blackbird1 on January 04, 2011, 07:37:16 PM
I think the side of the radiator with the cap is the cool side heading back to the engine, so there should be a big difference in temperature between that and the intake. When you measured the temperature at the intake was the gauge reading higher than normal?
Title: Wacky Temperature Gauge
Post by: jpc647 on January 04, 2011, 09:42:47 PM
Quote from: 20thanniver-ls;348381
Yep. As the engine temp rises the coil allows silicone fluid to enter the clutch and when it fills the grooves in the clutch body and plate  it engages  the clutch.

Would the outside temperature, being 30 as opposed to 70 prevent this from happening?

Quote from: Blackbird1;348386
I think the side of the radiator with the cap is the cool side heading back to the engine, so there should be a big difference in temperature between that and the intake. When you measured the temperature at the intake was the gauge reading higher than normal?

Yes, the temperature gauge was in the green, but just before where it hits the red mark. I understand there would be a slight difference, but what I'm trying to conclude is that if the gauge was accurate, that antifreeze should be well over 130, otherwise the constantly mixing/moving coolant would be much higher, right? I mean where it is on the gauge, the antifreeze should be almost boiling.
Title: Wacky Temperature Gauge
Post by: 20thanniver-ls on January 04, 2011, 09:48:14 PM
Honestly, I don't think so, because your engine temps would kind of almost cancel out the outside temperature with the hood closed, kind of like turning a heater a house. If the fluid is leaking out of the fan clutch that is a good sign of it maybe not working.
Title: Wacky Temperature Gauge
Post by: jpc647 on January 04, 2011, 09:50:29 PM
I don't notice any fluid leaking out of it. I looked for that, thought maybe it would be wet, or something. Again, this problem only happens when the outside temperature is low, in the 30'sish and down.
Title: Wacky Temperature Gauge
Post by: hypostang on January 04, 2011, 09:53:30 PM
When you raise the pressure of a liquid it raises the boiling point also , I would suggest trying an aftermarket gauge for at least a little while
Title: Wacky Temperature Gauge
Post by: thewestie on January 04, 2011, 10:39:41 PM
Quote from: jpc647;348412
I don't notice any fluid leaking out of it. I looked for that, thought maybe it would be wet, or something. Again, this problem only happens when the outside temperature is low, in the 30'sish and down.

  Ive got a aftermarket gauge you can have in worcester its a high quality Fisher auto parts temp gauge
Title: Wacky Temperature Gauge
Post by: jpc647 on January 05, 2011, 08:25:14 AM
you say have, like for free? Where in worcester are you? I work right off park ave.
Title: Wacky Temperature Gauge
Post by: thewestie on January 05, 2011, 09:35:48 AM
Quote from: jpc647;348462
you say have, like for free? Where in worcester are you? I work right off park ave.

 
greenwood st
Title: Wacky Temperature Gauge
Post by: jpc647 on January 10, 2011, 01:28:00 PM
Hopefully picking up the gauge today, and we can go from there.

I just understand why during winter the gauge says the car is running really hot, but on a 90 degree day, or a 70 degree day the gauge stays within middle to 3/4 of the green area. It baffles me. What sensors, etc could be affected by the cold? I guess I can try a new fan clutch, it's original as it is stamped ford.
Title: Wacky Temperature Gauge
Post by: tbirdsps on January 10, 2011, 04:26:21 PM
When this happened on my 85 Cougar 3.8 it turned out that the temp gage had it's own voltage regulator.  The Ford dealer changed it and all was well.
Title: Wacky Temperature Gauge
Post by: jpc647 on January 10, 2011, 04:39:30 PM
Did temperature affect it at all? Do you have any idea where the voltage reg is? You have the gauge shown here: http://www.coolcats.net/tech/general/8588base.html
Title: Wacky Temperature Gauge
Post by: tbirdsps on January 10, 2011, 05:52:52 PM
That looks like the same base instrument cluster.  I think the voltage regulator is on the back of the cluster.  In my case the gage ran in the red when under load like climbing hills and up on the L of NORMAL pretty much all the time when the engine was warmed up.  I changed the temp sender myself and that had no effect then I took it to the dealer and they replaced the regulator.  I don't remember but it wasn't all that hot out.
Title: Wacky Temperature Gauge
Post by: jpc647 on January 10, 2011, 07:43:29 PM
Quote from: softtouch;265873
When you say "turn the heat on" do you mean the blower?
How about if you turn the blower on with out the heat on? does that make the temp gauge go up?
Are the fuel and oil pressure gauges also affected?
What I am building up to is a possible flakey IVR.

Just out of curiosity, just for reference, if turning the blower motor on did make the temp gauge go up, does that mean the ivr is bad? I only ask because when i got home yesterday I turned the blower motor off, but left the heater setting to vent and the gauge moved a little. Maybe like the width of the needle. Barely enough to notice unless you were watching it. So I turned the blower motor to high, and it went up the same amount. Then I turned it to max ac(ac not connected) where the flapper in the HVAC system opens and the fan spins really really fast, and it went up a little more, just into the red. But the fuel gauge does not appear to move.

Now although the width of the needle isn't nearly the amount the gauge seems to be off, maybe it is a starting point. I will install the temperature gauge tonight or tomorrow night and go from there. But it may be slighly off, due to an electrical problem. What might cause this?
Title: Wacky Temperature Gauge
Post by: jcassity on January 12, 2011, 01:56:11 AM
short cut answer,,
if the ivr is bad, you will loose fuel and temp readings 100%,, on the base electronic cluster.

does your heater work on low or does it work on High only.?
Title: Wacky Temperature Gauge
Post by: jpc647 on January 12, 2011, 08:56:19 AM
The heater works on all settings. Maybe not on the low low one, but I think I did that. I think back in the day I clipped one of the coils on the variable resistor so that I could have the vent open, without the fan blowing. But it works normal on the other settings.

So we can rule out the IVR, as this is only my temp gauge. Sitting in my driveway, level, after a thirty five minute drive home, I did the testing about, where the temp gauge would move. The gas gauge did not appear to move even slightly.
Title: Wacky Temperature Gauge
Post by: jcassity on January 12, 2011, 10:03:32 PM
dont kill yourself trying to tear things apart.
get that temporary temp guage installed and compare what the cluster says to the temporary guage.

I suppose you did unhook the little red wire at the temp sender and connected it to chassis ground?

if so,, did it peg out to max?

If it does then im afraid you may be needing to take a couple readings on your temp guage wires, your looking for 12ohms.
Title: Wacky Temperature Gauge
Post by: jcassity on January 12, 2011, 10:34:13 PM
I feel like we can rule out the IVR , like any other person you talk to, you should get a second opinion.  I am 95% sure the ivr is not the problem.
Title: Wacky Temperature Gauge
Post by: jpc647 on January 13, 2011, 12:42:04 PM
I think I grounded it way back in time, thats easy, I can do that again. I'm not sure how I'm going to be able to use both gauges though, the one in the car has a different sender, and the temp gauge I will put in uses it's own. They both can't be in the same hole...
Title: Wacky Temperature Gauge
Post by: thewestie on January 13, 2011, 10:09:17 PM
Use the tee and nipple in the intake. The aftermarket gauge on the top and factory gauge on the side I'll be working in the yard on sat if you want to come by we can do it in my drive way.
Title: Wacky Temperature Gauge
Post by: jcassity on January 14, 2011, 01:56:23 AM
the external temp guage will have wires going to it,, so if you want,
just remove your lil single wire temp sensor, then install the aftermarket one, run wire n the car, zip tie the mofookie somewhere you can see it.
its just a test bed anyway,,nothing overcomlicated.  your just troubleshooting.

if your temporary sender doesnt fit the hole,, then figure it out, thats what we have to do all the time, but the sender needs to be touching water (submerged) to signal correctly.

in the time it took you to reply, you couldve (in 5min flat) walked out and grounded the guage, and answered your two year old question.
im just sayin,, its a simple cooling problem and there aint too many things to check before it becomes an engine component problem.
Title: Wacky Temperature Gauge
Post by: jpc647 on January 14, 2011, 12:54:09 PM
Quote from: jcassity;349670
in the time it took you to reply, you couldve (in 5min flat) walked out and grounded the guage, and answered your two year old question.
im just sayin,, its a simple cooling problem and there aint too many things to check before it becomes an engine component problem.

Not entirely true. When I responded I'm at work. I work 8-5(usually 6) monday-friday. It's a shirt and tie job, so I'm def. not going to go out in the parking lot and start wrenching on my car in expensive clothes. It's dark when I get home at night, and it's cold. So I can't do much. I try to gather up as much information as I can for when I do have some daylight to do the job(usually on weekends). But tonight, I will ground the gauge, and see what happens.

Quote from: thewestie;349627
Use the tee and nipple in the intake. The aftermarket gauge on the top and factory gauge on the side I'll be working in the yard on sat if you want to come by we can do it in my drive way.

Maybe I'm an idiot, but there isn't a t in my intake, lol.
Title: Wacky Temperature Gauge
Post by: hypostang on January 14, 2011, 03:41:08 PM
Quote from: jpc647;349692
Maybe I'm an idiot, but there isn't a t in my intake, lol.
  I think he meanshiznit an  auto supply house and get a T fitting , which I agree is a fantastic idea
Title: Wacky Temperature Gauge
Post by: BadTriumph on January 14, 2011, 06:09:55 PM
The problem with adding a tee to the coolant sensor is that you aren't getting a true reading anymore. The water doesn't flow through the tee, so you will get more of an ambient temperature reading instead of a true coolant temperature reading. I tried this before years ago and it was way off. If you are going to add an aftermarket gauge, it's best to remove a plug in the intake somewhere (if you have one) and install it there. If you don't have one, replace the factory sensor. Even if it's only temporary, you would know what the coolant temperature is really doing. You could have an indication of a more serious problem than a bad temp gauge.
Title: Wacky Temperature Gauge
Post by: jpc647 on January 14, 2011, 09:34:29 PM
Quote from: BadTriumph;349739
, it's best to remove a plug in the intake somewhere (if you have one) and install it there. If you don't have one, replace the factory sensor.

Does a factory 87 5.0 have an extra plug, somewhere? I don't think it does. I know my 1972 Cutlass has an extra plug, but I don't think the T-bird does. I'll have to check tomorrow.
Title: Wacky Temperature Gauge
Post by: thewestie on January 14, 2011, 09:52:40 PM
Quote from: jpc647;349754
Does a factory 87 5.0 have an extra plug, somewhere? I don't think it does. I know my 1972 Cutlass has an extra plug, but I don't think the T-bird does. I'll have to check tomorrow.

 
like i said I'll be home all day the new starter wont stop trying to start :( 
  if you want to come by call me Just got to run to fisher for a fender wall starter solenoid
Title: Wacky Temperature Gauge
Post by: hypostang on January 14, 2011, 09:58:54 PM
Quote from: thewestie;349755
like i said I'll be home all day the new starter wont stop trying to start :( 
  if you want to come by call me Just got to run to fisher for a fender wall starter solenoid

Say hello to Wayne for me :)
Title: Wacky Temperature Gauge
Post by: jpc647 on January 15, 2011, 12:08:54 PM
Quote from: thewestie;349755
like i said I'll be home all day the new starter wont stop trying to start :( 
  if you want to come by call me Just got to run to fisher for a fender wall starter solenoid

 
The starter, isn't it because of the jumper wire you used to connect the two points on the starter itself? It's a high torque one, right? I have a thread I made about it asking questions and such. Look here: http://www.foxtbirdcougarforums.com/showthread.php?30420-Need-Help-With-High-Torque-Starter&highlight=

It's been in my car like that for a week now, and it seems to have been fine. I've got some family stuff I have to get done first today, and then I can look at the car. I'll give you a call if I need help, thanks.
Title: Wacky Temperature Gauge
Post by: jpc647 on January 27, 2011, 08:25:26 PM
Quote from: BadTriumph;349739
The problem with adding a tee to the coolant sensor is that you aren't getting a true reading anymore. The water doesn't flow through the tee, so you will get more of an ambient temperature reading instead of a true coolant temperature reading. I tried this before years ago and it was way off. If you are going to add an aftermarket gauge, it's best to remove a plug in the intake somewhere (if you have one) and install it there. If you don't have one, replace the factory sensor. Even if it's only temporary, you would know what the coolant temperature is really doing. You could have an indication of a more serious problem than a bad temp gauge.

 
There doesn't seem to be another hole, is there some sort of a "T" that would allow both of them to be submerged?
Title: Wacky Temperature Gauge
Post by: jpc647 on January 27, 2011, 08:41:42 PM
Quote from: jcassity;349499
dont kill yourself trying to tear things apart.
get that temporary temp guage installed and compare what the cluster says to the temporary guage.

I suppose you did unhook the little red wire at the temp sender and connected it to chassis ground?

if so,, did it peg out to max?

If it does then im afraid you may be needing to take a couple readings on your temp guage wires, your looking for 12ohms.


It did peg... Is this bad? I send you a pm, but, should it be 12 ohms cold, or how, or what? I know I tested this way back, but we'll see this time around.