Underheating issue?

overheating
corolla

#1

I have a 93 Corolla that seems to run fine with one exception. The temperature gauge takes an awfully long time to register 50% (where I’m assuming it’s supposed to be).



Typically, the first couple miles it will register 0-10%. Then miles 5-10 it might show 25%. It isn’t till I’ve been driving for 10+ miles that it will show 50%, and sometimes it will later drop back down to 30%.



Other cars I’ve driven will be at 50% temp after only 1 mile and will stay at that temp.



Is this a concern? Could it be a faulty thermostat?



Thanks for any insight!


#2

Yes, replace thermostat


#3

This behavior suggests a malfunctioning thermostat.


#4

Agree! This type of thing only happens when your thermostat is stuck in the open position; just have it replaced.


#5

And, if you need some motivation to replace the thermostat sooner, rather than later, I can tell you that your “cold” engine is using much more gas than usual until it finally warms up. Also, some additional engine wear takes place under these conditions.


#6

—and don’t “el-cheapo” it. Ensure that you get a new t-stat gasket. Usually comes with the t-stat, but check and make sure. Other than that, also ensure that mating surfaces of the t-stat housing are “eat-off-it” clean and don’t over torque the bolts when installing the new t-stat/gasket.


#7

check coolant first- - -if there is none in there then the temp sensor could give faulty reading.

If coolant ok then repalce thermostat.


#8

Did you buy the car used? If so, I would suspect that it has no thermostat at all. Prev owners and used car lots tend to just pull them rather than replace them to solve overheating problems. As noted above, this causes gas mileage to go to pot.