Car Temp Not Showing...

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Ok I have a little bit of a problem. I have a 1993 Mercury Topaz and the temperature gauge does not move at all while driving.. It is bottomed out. Once I turn the car off the temperature gauge starts rising all the way into the red. What could this be? Is it something in the cooling system such as a thermostat, or is it somewhere else. Someone mentioned the sending unit but I have no fricken clue what that is.

Today I also just flushed out the radiator and added new anti-freeze/water 50/50 mix. It seems the temperature is not rising as much when I shut the car off. The car only has 76K miles on it but it was an old lady before that owned the car and I don't think anything was ever done with the cooling system. I might even have to flush it out again. :sigh:

Its my first car so I dont know much about cars but I really love working and learning about how to work on them. It took me a half hour to find the radiator plug and another half hour to finally get it open becouse its right above the suspension. :hi:

:banghead: :banghead:

posted by  EvilPodAE

Here is a pic of the Engine also. (

posted by  EvilPodAE

Same engine as mine, 1994 Tempo. I can already tell you the temp gauge on mine doesnt read right because if you look at my posts SOME damn sensor in the thing is telling the car it is overheating in gear even though when the gauge is getting close to hot I can touch the block with gloves and feel very little heat.

If you go to I've found that they have very detailed service manuals for most 80's-90's ford sedans online and its showed me a chitload of sensors and stuff I did not even know were on this fuel injected sumbitch that could be giving me this problem. Its real helpful. If they dont have that topaz try comparing it to the 90's 4 cylinder tempo.

For example:

Tempo / Topaz manuals @ ( d/80/12/6a/dd/0900823d80126add.jsp)

posted by  Blue_Frog

Wow... I have to say, that one really has me. :screwy:

posted by  DodgeRida67

Like you said to me in an earlier post Dodge..I think there are some screwy sensors going on in and about this engine. The problem is figuring out which effing one.

Like your half assed project by the way :mrgreen: .....I'm jealous like all hell :fu:

posted by  Blue_Frog

Dodge I am very jealus of you right now. LOL Ill be buying an 87 Camaro soon from someone at my job in the spring. I love that engine in your sig. Anyway I am almost certain now that it is the coolant temperature sensor. Reason is becouse it seems to be the guage that is the only thing that is acting screwy. But before I shell in $20 for this sensor should I try the therostat first?

posted by  EvilPodAE

I think a thermostat would be a waste of your money. If you think it's the sensor, go ahead and replace it. This one really has be. Everything is backwards and wrong at the same time. I don't think it would be the sensor but this one is crazy.

posted by  DodgeRida67

Well I am looking at it this way it has to be one of the following:

1. Sensor for the gauge.
2. Sensor for the computer. (Doubt it though, if it is then the car would be running bad)
3. Thermostat
4. Sending Unit (Where the hell is this? Someone mentioned it to me.)

posted by  EvilPodAE

See my post above about the engine being the same as my tempo. There is a very detailed online manual for that topaz / tempo at It will show you where the sensors and sending unit relating to the temp gauge is at if you search it.

posted by  Blue_Frog

It is either the sensor or the gage itself.

posted by  srober32

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