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?

[Superhawk996]

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?

There are several things going on here.

Fix the flaps - get new thermostat if necessary. I'm going to recommend the opposite of previous advice. Fix the flaps 1st -- engines aren't cheap.

The flaps provide proper warm up (i.e. quickly) and drive condensation moisture out of the oil. Air cooled engines don't like to run cold. Personally I had an engine come with my car as purchased that was wrecked by rust and condensation caused by running without flaps for who knows how long. There are other reasons related to engine running clearances too.

With respect to your temp gauge. That measures oil sump temperature -- the fact that it is running on the low end of the gauge is yet another indication that your engine oil is not running at proper temperature and may not be warming properly due to the flaps issue.

Nice graphic someone crated:


Note that when flaps are failed open you're constantly running cooling air across the oil cooler.