91 2.0 Engine temperature in cold weather - stevied
Question for you clever folk. I have noticed that in very cold weather, such as today, my car starts OK, and goes OK: temperature seems to go up and the auto choke gradually takes idle to standard level. My first ten miles were in stop start traffic and engine temp went up to halfway on guauge, ie normal. BUT, when on the M6 later in the journey, and all going fine seemingly, I looked at the guauge and it was almost on zero. My suspicion, based on absolutely nothing, is that the sensor is reflecting the outside temperature more than engine and when I slow down and there's less/no rushing air, it goes to normal.

Is my car about to blow up? Any ideas? It seems to be running fine... oil topped up, coolant at normal levels... etc. etc.

Confused.
91 2.0 Engine temperature in cold weather - Peter.N.
Is your low temperature reading accompanied by low heater output? If so, your thermostat is probably faulty, if not the gauge is.
91 2.0 Engine temperature in cold weather - stevied
An honest answer is: heater output was still warm, but when I stopped in traffic near Marlow, it did get a bit warmer.... but it was never actually cold.
91 2.0 Engine temperature in cold weather - Peter.N.
If the thermostat sticks open, as your speed increases so does the airflow through the radiator so the water temperature drops rapidly. The way to check is to start the engine from cold and see if the radiator gets warm before the temperature has reached normal, it should stay cold, if it doesn't you need a new thermostat, a relativly simple job.
91 2.0 Engine temperature in cold weather - stevied
The fan is still cutting in if that means anything, and the temperature has only gone down rather than up....
91 2.0 Engine temperature in cold weather - Peter.N.
Assuming that your fan thermostat is OK your gauge is reading wrong, possibly the sensor.
91 2.0 Engine temperature in cold weather - mjm
The cooling system in an MR2 is rather convaluted. The first thing I would check is the coolant level. I found it difficult to see the level in my daughter's car. There is a lot of pipework to feed the heater and the radiator. There are two large stainless steel pipes running to the front of the car and these, in this weather, must be doing a fair bit of cooling on their own. It may be that you have an airlock in one of the pipes.
Having read the rest of the thread, if the coolant level is ok then I would be looking at the thermostat.
91 2.0 Engine temperature in cold weather - bell boy
i would say its the weather
apparently its cold out
91 2.0 Engine temperature in cold weather - mjm
Another thought. Do you mean the radiator fan cuts in or the engine bay cooling fan?

If you are interested I have a repair manual stored on my hard drive, I can copy it to a cd rom and send it to you if it's any help.
 

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