# Scangauge on 1997 Altima - optimum coolant temperature?



## julian2 (Dec 10, 2009)

I just bought Scangauge II which is a very handy device for monitoring MPG, coolant temperature, and a bunch of other things. One thing I notice is that the water temperature only seems to get to about 145 deg F while driving on the freeway and about 154 deg F in traffic (with outside air temps currently about 53 deg F). This seems a bit low as the coolant thermostat on the Altima is supposed to open at about 170 deg F. Does this suugest my thermostat is not working properly? Should I change it? 

The heater comes on fairly quickly and the water temperature gauge on the dashboard comes up reasonably fast though it does seem to stay at less that half way. So it would seem that thermostat is kinda working but maybe it is stuck slightly open all the time. Is that possible? Anyone else tried using Scangauge with their Altima? What temperatures do you see? :waving:

How much difference in fuel consumption would a slightly higher operating temp make? The Scangauge measurement of fuel consumption is slightly depressing - these Altimas are not very good on gas no matter how carefully you drive 'em. 

:givebeer:


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## pulsar86 (Aug 13, 2009)

It is possible to have a thermostat stuck partially open. The air temp you have isn't very high though so that might be why the car is running so cool. Might be worth having a look at the thermostat though. A 170 thermostat is fairly low a lot of Nissans run 190's..


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## julian2 (Dec 10, 2009)

I haven't seen any other thermostats for this model Altima other than 170 deg F. But shouldn't I at least see temps around 170 if the termostat is working correctly. Any suggestions what to use instead?


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## pulsar86 (Aug 13, 2009)

Check to see that your cooling fan is not running all the time.


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## julian2 (Dec 10, 2009)

Nope - the cooling fans seems to be fine i.e. not running all the time or too much. Besides surely if the coolant in the engine is below 170 deg F, the thermostat should be closed and thus the hot coolant should not even reach the radiator. Thefore the fans shouldn't really matter that much in this temperature regime no?


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