S4gasm (LoTR)

autohaus only listed the "engine temp sensor", but taylorauto (link below) listed 2 different things. I know the first one listed is the one that fits my car, however i noticed there is a sensor under the expansion cooling tank, what would be the name of that sensor??

20v.org refers to the code that my car threw as a "coolant temp sensor", is that the same thing as the engine temp sensor? I'm assuming they are the same thing no?<ul><li><a href="http://catalog.eautopartscatalog.com/taylor/wizard.jsp?partner=taylor&amp;clientid=taylorautom otive&amp;baseurl=http://www.taylorautomotive.com/&amp;cookieid=1G00WKVG91PF0XQKZE&amp;year=1988&amp ;make=AU&amp;model=90-Q-001&amp;categor

S4gasm (LoTR)

i would to verify if it is actually bad or not before i spend 40 bucks on something i dont need.

Reggie

There is one for the gauge and one for the ECU

YucatanAudi

sensor. There are actually several other "temperature sensors":

1) HVAC coolant sensor/switch - <b>under</b> the upper rad hose connection at engine block. For those with Automated Climate Control. <i>{The Engine temperature sensor is not equipped on all models (to be phased in).}</i>

2) Coolant Temp Sensor/Switch - <b>above</b> the upper rad hose connection at engine block. This is the likely suspect if it is what your codes told you. It is linked to the ECUs for Fuel and Timing:

The coolant temperature sensor, located on the water outlet to the upper radiator hose, is an electrical thermistor with negative temperature coefficient properties. Negative temperature coefficient means that the change in resistance is inversely proportional to the change in temperature (as temperature increases, resistance decreases). The fuel control unit and ignition control unit share a single temperature sensor. Each ECU applies a regulated constant voltage to the sensor, and monitors the voltage in its circuit. As temperature increases, sensor resistance decreases, causing a decrease in the measured voltage of the circuit. By monitoring the circuit voltage, the control units can calculate the engine temperature, and adjust the air/fuel ratio and ignition timing to meet the specific demands of the engine, at that temperature.

You can test it with an Ohm meter or Multi-meter: COOLANT TEMPERATURE SENSOR
Resistance @ 20~C (68~F) Approx. 2.5K ohms
Resistance @ 80~C (176~F) Approx. 200-300 ohms

False Readings of a faulty Coolant Temp Sensor can come from (the sensor is good, but you have another problem):

-- Poor connections or corroded connector terminals at sensor.
-- Open circuit between fuel control unit terminal #3 and sensor connector terminal #2.
-- Grounded circuit between fuel control unit terminal #3 and sensor.
-- Faulty sensor.



3) Raditor Cooling Fan Switches:
a) Cooling Fan - bottom edge of radiator
b) Cooling Fan After Run - back edge of valve cover

4) Temp Sensor-Guage: below coolant connection on cylinder head.

Those are all for a 10v. I think they are pretty much accurate for a 20v, but not sure.

YucatanAudi

Remove it and test it in the house with a pan of ice water and a pan of boiling water along with your multi-meter or ohm meter.

Those are "roughly" readings. If it is close under those conditions, it is operating. Doesn't have to be perfectly on the money and the official charts allow for some leeway.

S4gasm (LoTR)

great, thanks craig...yeah i already spotted #2, just need to test it now.