Temperature Gauge, Seems a bit too low? Options

[Serhey]

my temperature gauge always seems to be a bit too low, now i know its not good for the car to over heat but i also dont think its a good thing for it to be under. Now the car runs fine, atleast as far as i know, ive driven and owned cars before this celica, and it doesnt seem to act any differently, accelerates fine drives fine even driven it for 5 hours at a time and it was fine (i've only owned it for 2-3 months) but whenever i drive it the temperature gauge on average stays maybe 1/5 or at best 1/4 of the way up, way below the middle. could the gauge itself be broken or is it something bigger then that?
i've also turned off the heat to see if it had any affect on it and it seemed to go up a tiny bit but thats not the way i want to fix it

[delusionz]

The thermostat is likely stuck open.

Remove your thermostat from the housing, refit the thermostat housing and attach a garden hose to it and blast out the cooling system. Attach something to the top radiator hose to drain it out away from your engine bay and paint work. -- Blast it out until water runs clear, and turn on your heater so it opens up the flow through the heater.

After this, remove the thermostat housing again and refit with brand a new thermostat and gasket.

Refill with 2.5 liters of coolant and top up the rest with distilled water.

[Bitter]

don't use the hose, you'll never get a 50/50 coolant mix. just drain and fill the cooling system after replacing the thermostat.

[delusionz]

It's not entirely important to have a bang on 50/50 mix. What is important is to blast out the brown crud.

The cooling system is 5 Liters in total (I don't know what that is in imperial), so just make sure 2.5 - 3 Liters of coolant concentrate goes in before topping up with water.

Idle the engine for a little bit and re-top up as necessary

This post has been edited by delusionz: Dec 20, 2009 - 6:23 AM

[Bitter]

its pretty important in chicago to get the 50/50 mix, we do see overnight temps as low as -25F (-32C). also, tap water has chlorine and minerals in it which are very much not good for the cooling system, chlorine is highly corrosive to aluminum and the minerals can buildup and create clogs.

just drain the block and radiator and refill. if you feel the need to flush the block then do so, but be sure to re-drain it and flush it with some distilled water or blow the water out of it with compressed air. typically though the block does not need flushing, its the heater core and radiator which need it.

[Serhey]

yeah also, today i left my car running for a few minutes and it warmed up and the temperature showed maybe 2-3 mm under the middle. and when i started driving i felt so much more power and it was so much smoother, but within a mile or so it dropped back down to like i would even say 1/8 of the way from the bottom. can someone please explain the draining process, in a way a 17 year old with not much car experience would understand. i apologize for my amateur knowledge in cars.

[Bitter]

need to change the thermostat, theres i think a few how-to's here. a haynes manual would be a good thing to get also. any how-to's for the 93-97 corolla are the same procedure as well, same engine. i suggest using a toyota thermostat, they work the best and cost the same as a good one from any parts store. you'll need coolant to replace what spills.

where in chicago are you?

[IBTINTN]

I had the same problem with my Celica. Driving around town the temp would rise to almost half way. As soon as a hit a speed over 80kms it would drop down to just over the cold mark. As everyone has said change the thermostat. Mine was broken and when I put a new TRD low temp in I had heat again. Never had a problem since.

[Serhey]

need to change the thermostat, theres i think a few how-to's here. a haynes manual would be a good thing to get also. any how-to's for the 93-97 corolla are the same procedure as well, same engine. i suggest using a toyota thermostat, they work the best and cost the same as a good one from any parts store. you'll need coolant to replace what spills.

where in chicago are you?

thanks guys, that seems fairly easy to fix. i live in prospect heights, right by wheeling.

[Bitter]

cool, but too far to come lend a hand or swing down by me for a hand.