Cooling flap system on a '74 2.0 stuck open Options

[Lockwodo]

Hi all. As I work through the maintenance issues on the '74 2.0 I bought recently, I noticed that the cooling flaps are wide open (as they would be when engine is warmed up) all the time. Since this is the default position when a thermostat fails, I'll be checking the thermostat and wire/pulley mechanism. But just wondering what priority resolving this should have? It's not like I don't have plenty of other things to take care of (IMG:style_emoticons/default/smile.gif)

The car starts from cold, idles and runs well. I live in an area where it's unlikely I'll be starting and driving the car in temperatures below 60 degrees F. What do you think?

[Lockwodo]

All great advice! Here's a related question: The temp gauge on my car generally registers close to the bottom end of the scale and I can imagine these gauges can be funky. I'd like to use an infrared temp gun to measure actual engine temperature. Which points on the engine would be good to "shoot" and what readings would be considered normal operating range?

[bkrantz]

All great advice! Here's a related question: The temp gauge on my car generally registers close to the bottom end of the scale and I can imagine these gauges can be funky. I'd like to use an infrared temp gun to measure actual engine temperature. Which points on the engine would be good to "shoot" and what readings would be considered normal operating range?

If the circuit is open anywhere between the sensor and gauge, it will read at the bottom of the scale and never move higher. Same thing if the sensor has failed "open".

You can test the gauge by grounding the lead. That should peg the gauge beyond "hot".

[Lockwodo]

All great advice! Here's a related question: The temp gauge on my car generally registers close to the bottom end of the scale and I can imagine these gauges can be funky. I'd like to use an infrared temp gun to measure actual engine temperature. Which points on the engine would be good to "shoot" and what readings would be considered normal operating range?

If the circuit is open anywhere between the sensor and gauge, it will read at the bottom of the scale and never move higher. Same thing if the sensor has failed "open".

You can test the gauge by grounding the lead. That should peg the gauge beyond "hot".

Thanks bkrantz. My complacency over the cooling flaps issue has evaporated. I'll check the gauge and the circuit if need be, and replace the sensor if it's toast. Question: can the temp sensor be replaced without draining the crankcase first?