Faulty temperature gauge?

[dmg1969]

I have a 2000 Escort ZX2 with a little over 61K miles on it. About a week ago I noticed that my temperature gauge seems to be acting up. Even after sitting all night in 20-30 degree temperatures (I live in central PA), it doesn't go down past about 40-45% up the normal range. This morning I came into work and it sat for about 3 hours in 25 degree weather. I drove it up to the bank (1 mile down the road) and when I pulled up to the drive-through, the gauge was already up to the upper limits of the normal range. When I drove away from the drive-through, it dropped to about 2/3 of the normal range. I can actually see it flucuate even though temperature changes should be so gradual, you should not notice them. Does this sound like a faulty gauge or something more? I'm coming up for inspection at the end of the month and might have them look at it depending on how much fixing the gauge would be. Thoughts?

Dave

[AltecZX2]

sound like a bad, or incorrect part

[dmg1969]

OK. What would be involved with replacing it? Is this something that I could do or is it better left to the dealership?

Dave

[pre98zetec]

probably need a whole new instrument cluster

[AltecZX2]

cluster?...just sounds like the thermostat might be wrong

[Paul78zephyr]

Im sorry but I have to say I just can't believe the guy who told you you probably need a 'whole new instrument cluster'. Based on what? The 'replace the most expensive and least likely to fail part before I even look at all other possibilities first' theory? Thats is just so stupid!!! Im suprised his first response wasn't that you needed a whole new interior! Boy if you said you car pulled to the left he'd tell you you need a whole new steering wheel!

Rant over.

Based on the obviously 'crazy' readings on your guage, but the fact that you mention no other apparent problems with your car - ie overheating, underheating, drivability, etc - I would not suspect a thermostat or other 'real' cooling issue. I would highly suspect a problem in the temperature guage SYSTEM which could mean its the guage, the instument voltage regulator (IVR, part of the instument cluster), the sender unit, or a wiring problem between the guage/IVR and the sender. Now yes, thats alot of stuff that could be wrong but those are all POSSIBLE causes. Now, I do not think it could be the IVR as this regulates voltage to ALL the guages and they all would be acting 'crazy' not just the temp guage. With any guage probelm on any car I always look at the sender unit first. They are the things that are most exposed (fuel sender submerged in gasoline, temp sender cooled/baked in coolant, etc). Its not always the sender, but its USUALLY is.

Based on my similar experience with a 'crazy' temperature guage on my 2001 ZX2 I would suggest that a PROBABLE cause is a faulty sending unit or a leak at the sending unit, which was the problem I discovered. Unlike most temperature sending units on almost every other car Ive owned that screw into a threaded port (NPT pipe threads) to be in contact with the coolant, the sender on the ZX2 is sealed to its port on the thermostat housing with an o-ring. I found the o-ring was leaking a bit and the coolant - which is very conductive (due to its alcohol content) leaked into the little two wire connector on the top of the sender and this was causing the signal (resistance readings) from the sender to be fouled up and hence the 'crazy' readings - like never going down or seeming to warm up in just a few seconds.

Looking at the engine towards the drivers side (back of the engine) look for the black plastic thermostat housing. Sitting here in front of my computer my recollection is that its located beneath the coil pack. There are two almost identical looking senders mounted on it. One points sort of up and the other points sort of down. Its the down pointing one that is the temp guage sender - the other is the engine temp sensor and is used by the PCM. After driving my car one day and having the 'crazy guage' issue I immediatly looked under the hood, found the senders (I had to figure out that the bottom one was the temp guage sender) and saw some coolant on the connector. I removed the connector, dried all the coolant from the sender and wires side of the connector (it was all wet inside) and reinstalled - immediatly my 'crazy' guage had gone sane! Now as far as the leak itself I think Ive just been lucky as I wiggled the sender a bit and the o-ring seems to have found a possition it likes to stay sealed in. This happend a year ago and I have had no 'crazy guage' since then. Just for the record, at the time thi happened I called the parts dept at my Ford dealer (where I bought my ZX2) and the guy told me they do NOT sell the o-ring seperately - you need to buy the entire sender at around $25 (thats my recollection of the cost). The o-ring should be like a $.50 part but Ford does not service it seperately. To me that's stupid - its the same as any other seal or gasket that they service, but there we are.

So I would start there based on my experience, if you see no leakage at the sender, then I would suspect the sender has failed (or is failing intermittently) but Id start by looking for leakage.

If you wish we can discuss further either here or you can PM me.

Please click here to check out my 78 Zephyr at my crappy Cardomain webpage

Good luck,
Paul

[pre98zetec]

my contour instrument cluster had a faulty temp guage in it, when i got a new one from the junkyard (a whole 5 bucks.. costly? no.. I think not) my temp. guage worked fine.

think what you want

btw, did I say that was his problem? no.. it was a mere suggestion. apparently you took it as a 'heres your exact problem' post.

[Paul78zephyr]

Originally Posted by sk8ter_in_ny

probably need a whole new instrument cluster

Uh,
That sounds pretty definative to me. But fair enough...

As far as instrument clusters go I think either you have a great junkyard with really low prices or more likely its that Contours will outnumber ZX2s in a junkyard at least 20:1. Ford 'dumped' so many Contours on the market when they made them (rental fleets, leases, etc). The ZX2 was always a 'niche' car especially with the dramatic drop in sales for all coupes after the mid-to-late 90s. Part prices (used or new) are based on suppy/demand. Most, not all, junkyards will get $50+ for a complete ZX2 cluster. The $5 for the Contour cluster is about what I would think. If this same yard wanted $5 for a ZX2 cluster that would really supprise me.

I still say based on my experience if you have a guage problem check the sender first.

Paul

[pre98zetec]

Originally Posted by Paul78zephyr

Uh,
That sounds pretty definative to me. But fair enough...

As far as instrument clusters go I think either you have a great junkyard with really low prices or more likely its that Contours will outnumber ZX2s in a junkyard at least 20:1. Ford 'dumped' so many Contours on the market when they made them (rental fleets, leases, etc). The ZX2 was always a 'niche' car especially with the dramatic drop in sales for all coupes after the mid-to-late 90s. Part prices (used or new) are based on suppy/demand. Most, not all, junkyards will get $50+ for a complete ZX2 cluster. The $5 for the Contour cluster is about what I would think. If this same yard wanted $5 for a ZX2 cluster that would really supprise me.

I still say based on my experience if you have a guage problem check the sender first.

Paul

yes the prices are awesome, i just got two brand new strut assemblies w/ springs for 70 for both sides. that junkyard actually has close to 30 ZX2's,, there was only about 5-7 contours there.

this guy doesn't want anything from the cars but the motors that why his prices are sooo cheap.

[Paul78zephyr]

Originally Posted by sk8ter_in_ny

yes the prices are awesome, i just got two brand new strut assemblies w/ springs for 70 for both sides. that junkyard actually has close to 30 ZX2's,, there was only about 5-7 contours there.

this guy doesn't want anything from the cars but the motors that why his prices are sooo cheap.

THIRTY(!) ZX2s in one place? WOW! What is the name of and where is this junkyard, please? I have 3 junkyards that I frequent with about 20 miles of my location here in eastern MA. Not one has ever had more than two or three ZX2s. And they all get $$$ for almost any ZX2 part.

Paul

[pre98zetec]

norths auto crushers, it's in akeley PA.. thirty was an estimate but i can tell you theres ALOT more then contour's there. I can get you the number if you'd like. He doesn't ship though.. if you need anything quick though you gotta get on it cause he crushes cars after theyve been there for a little bit so his selection is always changing.

this is the only junkyard around here with more than 5-10 ZX2s, and doesnt charge an arm and a leg.. most of the junkyards with good stuff charge 4 times more then it would cost to buy it NEW from ford, its rediculous.