Bad temp gauge - how hard to replace?


Sedanman64
03-10-2011, 03:24 AM
I've had cooling problems with my '94 escort 1.9 ever since I bought it - first it was overheating, then not warming up. All temp sensors have been replaced, and now the temp gauge barely moves when the car is fully warm so I'm assuming it's bad. Problem is, Ford and my local parts stores do not stock this part. I'm okay for a few months until it gets warmer outside, but need to resolve this. Any good sources for used parts? And how hard is this to change?

My Haynes manual shows this procedure (removing the inst. cluster) with the steering wheel off, but does not say you have to do that. It also does not tell how to remove the gauge - am I going to have a bunch of fragile plastic clips to deal with, or is getting the gauge out straightforward? I'm getting near to selling this car, but it may not happen before I have to deal with this. Thanks!

AzTumbleweed
03-10-2011, 06:12 PM
The gage just plugs into the connectors. Just pull it toward you and it comes right out. Just like unplugging an electrical cord from a wall outlet. I don't take my steering wheel off but I take the four bolts out that support the steering column so the steering wheel is sitting in my lap while I work. While you are in there make sure you check your panel lights. A good time to change any burnt out bulbs. Hope you have checked the sending unit first.
:2cents:

denisond3
03-11-2011, 12:32 PM
Have you done the simple test of the gauge? With the ignition 'on' but the engine not running, unplug the single wire connector for the sensor, and see if the gauge drops to Cold. Then very briefly short the lead inside that connector to ground. The gauge should shoot over to the extreme right side - at "H". If it does that, then the gauge is working okay. The single wire connectors can get weak. I wrapped a thin piece of copper wire around the post that the connector fitted over, to make a better connection. And the metal tube that the sensors (two of them on your car) mount on needs to be well grounded where it bolts to the bell housing.

I have had gauge problems with two of my 2nd gen. Escorts. Both problems were fixed by repairing the feeble ground connections at the negative terminal on the battery. I took the several wires from that 'connector' & soldered all of them together, and used a heavier wire soldered to the bundle, and grounded to the body of the car at the bolt behind the battery where they negative battery cable is grounded.

Its also possible to have dirty connections on the back of the instrument cluster. Just removing and replacing the gauge might clean the contacts. I use a pencil eraser or a strip of 600 grit emery paper to clean up the contacts on the back of the cluster where the three long narrow connectors go.

mightymoose_22
03-13-2011, 08:05 PM
Chances are that your gauge is just fine. This is an old car ad likely just needs some maintenance.
The overheating could have been caused by a few things, but it sounds as if you have resolved that already?

The overheating likely caused some plastic parts near the thermostat to melt, and a bypass valve around your thermostat is open now, which prevents the engine from warming up.

You may need to change the housing that the thermostat is mounted in. I have found this is at the part stores labeled as a "water outlet". If I remember correctly it sold for around $40. The part is simple to change, but be prepared to deal with coolant drainage.

If you are sure your radiator and thermostat are good, consider changing this part. It is likely the original, and is likely bad after having an overheating problem.

It sounds to me like your gauge is working fine- it is telling you that you have an overcooling problem, and this thermostat bypass is a common cause.

Sedanman64
03-18-2011, 12:02 AM
Thanks, guys.

denisond3 ; I will take a look at the wires as this could be the case. The gauge is not totally "dead", and sometimes moves all the way up to the "c" but never further.

mightymoose 22 - Yes, I've been through the themostat removal/replacement routine several times and finally had a shop seal it up as I kept getting leaks. When I had the housing off the ball inside appeared to be moving freely, but I don't know if that means it's okay. If I have to pull the cooling system apart again I will sell the car - it's just getting to be too much trouble. It's odd how the first I buy of any used car is great, but the following ones of the same model are always more troublesome...

Sedanman64
03-18-2011, 12:04 AM
PS - when I had the therm. gasket replaced last fall and told them the car was not warming up, they checked it with some kind of laser and said it was. It's putting out less heat though, although my last escort (tracer, actually) had the same problem. The heater was fine last winter, and the overheating problem actually occurred before that.

mightymoose_22
03-18-2011, 07:42 AM
Well, handle it how you like, but just know that what you are describing sounds exactly as if the housing needs to be replaced. As long as coolant is bypassing the thermostat the engine will not reach normal temp.

It is a bot of a nuisance to have to drain coolant, but changing out the housing can be done in an hour or so. It isn't that big of a job- just messy.

rhandwor
03-27-2011, 05:38 AM
Well, handle it how you like, but just know that what you are describing sounds exactly as if the housing needs to be replaced. As long as coolant is bypassing the thermostat the engine will not reach normal temp.

It is a bot of a nuisance to have to drain coolant, but changing out the housing can be done in an hour or so. It isn't that big of a job- just messy.
Dorman used to make a metal housing original equipment is composite material.

zzyzzx2
04-05-2011, 01:42 PM
Well, handle it how you like, but just know that what you are describing sounds exactly as if the housing needs to be replaced. As long as coolant is bypassing the thermostat the engine will not reach normal temp.

It is a bot of a nuisance to have to drain coolant, but changing out the housing can be done in an hour or so. It isn't that big of a job- just messy.

True, but supposedly the housing bolts like to break.

Sedanman64
04-06-2011, 05:34 PM
Update: After reading the above comment about making sure the metal tube bracket is grounded, I went and checked mine as I thought the tube was no longer attatched to the bracket and this is indeed the case. So I went through the hassle of puting in a ground wire (had to take out the air box to get to a place to run the wire to, dropped a socket in, and then had to take out the rest of the air tubing in the fenderwell :mad: ). When I started the engine the guage started to work, but the engine fan came on before the engine was warmed up, and a "check engine" light came on.

So I had no idea what was going on and thought the ground wire might be the problem, and was frustrated at that point about an hour into it and tore the ground wire out. Stangely enough the gauge still worked but the check engine light did not go out. Since I was due for an oil change, I had the shop check it and they said one of the sensor wires was loose causing the fan to come on early. So now I'm back to square one. I swear I never have this much trouble working on my '64 Falcon - I could have changed the radiator in that car in the same about of time! I will get back to the ground wire (guage not working now) when my frustration level has calmed down.

zzyzzx2 - EXACTLY! One of my bolts was very hard to turn, and I did not have metric taps so that's why I took it to the shop to take care of. Breaking off the bolt was the last thing I needed to happen.....

Sedanman64
11-16-2011, 02:45 AM
and 7 months later.....I fnally got around to hooking up a ground wire from my temp sensor tube (which had come loose from the bracket that grounds it to the trans bolt), and now my temp guage appears to be working fine. In 40 deg.f. weather here in Seattle, the needle on the temp guage settles just slightly to the left of center on the "O"
in NORMAL. Since it was ungrounded and not working all summer, I never really knew how hot the engine was running.

It takes at least ten min. of driving for it to get up to that point after a 5 min. warmup (we're down to about freezing tonight when I tried this) and the heater just does not put out much heat. If I drive the car for an hour, the temp guage goes up a tad, but the heat is much warmer. I don't remember it being this cold before the shop replaced my thermostat last fall, so doubt it's the heater core and am thinking it's the thermostat housing, as mentioned earlier. But my shop has had a hard time finding one (although I just found one on o-Reilly's)

So does that position of the temp guage sound about right for cold weather but fully warmed up? I'm sure each car varies. I'm trying to decide if they put in a colder thermostat when they replaced the gasket (I told them not to as it was new and worked fine) or it's the housing. They'd probably have to take it apart to decide, but from what I recall last fall the thermostat they put in was colder than the one I had, although they said it was the hottest one they could find. I did a search online for the part number and didn't come up with anything; F8C78575 - AA Does that look familiar to anyone? I'll be calling my parts store to double check the heat rating of the one I installed previously.

zzyzzx2
11-16-2011, 09:14 AM
So does that position of the temp guage sound about right for cold weather but fully warmed up?

http://www.feoa.net/modules.php?name=Forums&file=viewtopic&t=65211

zzyzzx2
11-16-2011, 09:18 AM
zzyzzx2 - EXACTLY! One of my bolts was very hard to turn, and I did not have metric taps so that's why I took it to the shop to take care of. Breaking off the bolt was the last thing I needed to happen.....

Last time I was in a junk yard, I removed one (for practice) and broke 2 out of 3 bolts that hold on the thermostat housing.

Sedanman64
11-17-2011, 04:17 PM
Thanks, zzyzzX2 - looks about the same position of mine. You'd think "warmed up" would be closer to the middle. I've gotta stop by the shop today so we'll see what they say about the housing. As for the bolts, that was going IN, with clean threads and thread lubricant/anti seize!

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