coolant gauge (not moving)??

[hardtorn]

I have just give my tax return for a 1992 MTX.
I had driven the car about 2 mths ago. Did not notice any problems with the temp gauge. How ever... The car has sat out side in the snow for 2 mths now. The dude was holding it for me. It was no driven. I went to pick up the car last night. On the way home it felt as though the Heat was not up to par for an SHO. (I have 2 others, both 94 ATX) So as I watch the gauges I see that even after the 20 min. drive home... The temp/coolant gauge was still stuck. Had not moved a bit. The heat was working. It just never got really hot. I drove it again this am... same thing!
Could my thermostat be stuck? What other things would cause this?
The car runs great.... any Ideas...?

 

[projectSHO89]

If you have heat, the thermostat is at least somewhat okay.

Look to see if the wire came off the Temp Sending Unit. That would explain your no guage indication.

Steve

 

[ckinart]

Replacing both the thermostat and the gauge temperature sending unit is a relatively cheap and easy job. If you have any doubts/concerns (which you obiously do), I would suggest replacing both.

 

[sdpatt]

One word: theromstat.

 

[projectSHO89]

One word: theromstat

If it moved some, I would go for that.

His never moves. Most likely a problem on the measurement side.

Steve

 

[hardtorn]

UPDATE
I dropped in a new Thermostat last night. everything went well.
Did a System flush prior to the new stat.. Coolant system is working well now. Heat is working up to par with my other SHO...
However!!!!! The Temp. gauge is still not working like it should. It did move a bit.
But the needle never moved up out of the blue (cold area) on the gauge.
After some reading here I see that many think it could be the ECT! (electronic coolant temp. sensor) I think thats what ECT is for right.
Well if it is that now... some one tell me were its at on the car, how long will it take to change it, How much $$$ (work done by me)
And should they have it at the auto parts store?
Or do I need to order it from Ford.

Any other Ideas about what could be wrong... let me know

 

[sdpatt]

What thermostat and temperature setting did you install?

 

[SHOZ123]

Change both sensors. The ECT sender has two wires and goes to the PCM and you do not know how well it is working. The single wire sensor is for the temp gauge and it is obviously not working well.

 

[ckinart]

hardtorn,

I just went through a similar dilemma not too long ago, and ended up replacing both the thermostat and the gauge temperature sending unit. As mentioned above, this sensor has one wire coming off of it, and is located just to the left of the thermostat housing, when standing on the drivers side of the car. This sending unit provides a signal to the gauge in the dash, which is most likely what your problem is. This part is very cheap ($5?) and easy to replace.

The Engine Coolant Temperature (ECT) sensor has two wires coming from it, and is located to the right of the thermostat housing when standing on the drivers side of the car. This sensor provides a signal to the PCM, which in turns schedules the cooling fan to come on and off when required.

I made some enquiries (to a few SHO owners more "in the know" than me) when I was doing similar work, and was told that ECT failures are relatively rare, and this part is quite a bit more expensive.

For the relative cost and effort involved, I would just replace the gauge temperature sending unit for now, and see how you make out. If after that you find reason to believe that the ECT sensor is expired (resulting in improper cooling fan scheduling), replace it then.

Good luck!

<small>[ February 18, 2003, 10:00 AM: Message edited by: ckinart ]</small>

 

[jelloslug]

FYI the 2 wire sensor (the ETC sensor) is around $18 and you need eather a 25mm deep well socket or 1" deep well socket to get it off.

 

[jshosonak]

I just replaced my thermostat about two days ago. Prior to replacing it my guage didn't move off of blue and heat was minimal.

Since the replacement my heat has returned and the guage moved to normal...however, no matter how far I drive the needle never goes above the "L" in "Normal". I would think that the longer I drive the engine temp. would rise and hense be indicated by the temp. guage.

Is this normal or should I look at replacing the ECT?

 

[AutoSHO]

jshosonak:
I just replaced my thermostat about two days ago. Prior to replacing it my guage didn't move off of blue and heat was minimal.

Since the replacement my heat has returned and the guage moved to normal...however, no matter how far I drive the needle never goes above the "L" in "Normal". I would think that the longer I drive the engine temp. would rise and hense be indicated by the temp. guage.

Is this normal or should I look at replacing the ECT?

That is pretty normal for a 180 degree thermostat in the SHO. Mine runs right on the AL.

 

[bradman]

I agree the temp sending unit is the likely problem. The ECT should throw a code if it is bad.

<small>[ February 19, 2003, 02:47 AM: Message edited by: bradman ]</small>

 

[SHOZ123]

ECT won't throw a code until it is out of range. Until then the PCM is adjusting fuel mixture and timing by it if it is out of calibration. The only way to know if the ECT is operating properly (without a voltmeter) is to know for sure your temp gauge is accurate and what the letters mean.

This can be done with a analog thermometer.

Drain the cooling system and fill with water. Take the upper radiator hose off and bring engine to temp. Watch the upper hose as the t-stat opens and closes. Using the thermometer measure the temp of the water exiting and compare it to the gauge. Make sure you have a slow trickle of water entering the radiator to make up for what is lost.

Or you could get a cheap (~$40) non-contact IR thermometer and read the temp under normal conditions. IR thermometers

But until you know what your letters mean wrt an actual temperature number the whole thing is a guessing game. Once you know the actual temp compared to the numbers you can guesstimate the ECT condition by seeing if the fan comes on at what should be 210F or so. Again the IR thermometer works great for this.

 

[hardtorn]

Problem ... No MORE!

I put in the "temp sending unit"
One wire pop off the top. Quick and easy install.
Maybe took 10 min. The part was only $4.98 at auto zone. Took me longer to drive home than to put the part on the car.
The temp gauge works fine now.
Thanks all for your help..... AGAIN!
thumbs_u