C4 Tech/Performance L98 Corvette and LT1 Corvette Technical Info, Internal Engine, External Engine

Below normal temp

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Old Jun 30, 2012 | 09:00 AM
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Default Below normal temp

Good morning friends, normally people post here about their coolant temp being too high and how that worries them. Well mine is the exact opposite.
Drove the car to work yesterday and had the low coolant light on briefly, did a quick check and found it to have sufficient coolant. But noticed that instead of it normal running temp of 193-200 it was running 183-190. Staying mostly in the 184 range. In traffic it would climb up as it normally does etc. I guess my main question is what would cause it to run cooler than it normally does? AC blows cold & heat blows hot. I added about 2 quarts of coolant into the overflow when I got home to be on safe side. 89 auto with no mods
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Old Jun 30, 2012 | 11:57 AM
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Maybe the fan switch is stuck on. Wrong or no thermostat?
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Old Jun 30, 2012 | 12:02 PM
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Fill and burp the radiator. You may have to repeat the service after the car sits overnite.
Then take it for a drive.

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Old Jun 30, 2012 | 02:22 PM
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Coolant loss on any '89 should have you looking at #7 for symptoms of a leaking head gasket.

Scan for Coolant Temp Signal/Temp to see how it compares to the Display.

Thermostat needs coolant - not air - for it to work right so recheck once you've got a complete fill and no air in it.
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Old Jul 2, 2012 | 03:23 AM
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I suggest a new radiator cap. It controls the flow of coolant in and out of the coolant overflow tank and can cause a low coolant light if it's bad (happened to me).
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Old Jul 2, 2012 | 09:09 PM
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going to try to burp it to make sure no air is in system then see how it runs. I replaced rad cap last year but that doesn't mean it hasn't gone bad. I also suspect that the thermostat might be stuck slightly opened even though heater blows hot (just a guess).
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Old Jul 4, 2012 | 06:50 PM
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Thermostat was stuck opened. Replaced but first drilled 2 tiny holes on the replacement thermo. Didn't have to burp it. Took the opportunity to clean TB
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Old Jul 5, 2012 | 09:46 PM
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seabright, you're explanation about the function of the thermo is absolutely correct (according to my research) & logical but I can't explain why now it runs at normal temp after I've replaced the thermostat. if the sensor was bad it would still show low temp. If it was due to lack of coolant then it would overheat. When it was stuck open, the car would get above 210 in traffic but once I was cruising it would go as low as 175 but once I changed the therm it now hangs around its normal 190-200 range. I'm perplexed but pleased that it is back to normal.
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Old Jul 5, 2012 | 10:17 PM
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Your Thermostat will Modulate when it's cool outside, and open more often as the outside temperature increase's. Eventually if it's warm enough outside the Stat will remain wide open...now you rely on the radiator/fans to keep the temps in reason.

Mine stuck in the winter one time, and I could not get above 150f and my heater Suffered greatly.
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