T-stat install.....WTF is going on?
Thread Starter
Drifting
Joined: Feb 2007
Posts: 1,844
Likes: 12
From: Alpharetta Georgia
T-stat install.....WTF is going on?
Put in my 160 T-stat from southerncarparts.com and everything seems fine. The car, without reprogrammed fans, runs ~180deg while moving....I have seen as low as 176. However, what I don't understand is the temp at idle. Sometimes, it will hold 199deg for idle coolant temp. Sometimes, it wavers between 212deg and 217 deg for idle temp. When its holding 212deg, it goes up to 217 and then back down to 212 in about 1.5 minutes and consistently does it over and over again. Regardless of what idle temp its holding, the second I start moving, the temperature IMMEDIATELY starts dropping at a pretty rapid rate to the ~180deg driving temperature. What is causing this?
Team Owner
Joined: Jan 2007
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From: In the woods looking for my thrown putter.
St. Jude Donor '13, '15
Well, the idle temp going between 212 and 217 may be the fans coming on cooling down the coolant. I am not sure what the factory fan programming is so maybe someone else can help. The temp dropping down when you are moving is because you have airflow against the radiator which you do not have when sitting still.
Team Owner
Joined: Feb 2001
Posts: 27,254
Likes: 136
From: Short Hills, NJ
You might still need to get some of that air out of the system, maybe run the car with the coolant reservoir/overflow tank cap off to solve that?And of course even once that's fixed the car will still run hotter during a prolonged idle than it will once moving unless the fan settings are reprogrammed or a Fan Module is installed.
Melting Slicks
Joined: Sep 2005
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From: merritt island fl
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Also, the water flow rate increases substantially when you start moving and the revs increase.
Pro
Joined: Apr 2007
Posts: 663
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From: Arvada CO
You didn't say what the ambient temperature is when you are idling, however before I had my fans reprogrammed, all the temps you mentioned at idle are what I saw on my car. Once I started moving, the temps immediately dropped.
Pro
Joined: Sep 1999
Posts: 518
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From: South Florida
it took me a while to get all the air out of the system, you need to burp the system, read glennhl's post here http://forums.corvetteforum.com/show...t=coolant+burp
Thread Starter
Drifting
Joined: Feb 2007
Posts: 1,844
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From: Alpharetta Georgia
Gotcha. I burped it for about ~5 minutes yesterday, guess there is still a bit of air in there. I understand that when I start moving, airflow over the radiator will start cooling it down, but if you guys saw how fast it dropped, you would understand that there is a bit more to it than that.
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Instructor
Joined: Apr 2007
Posts: 154
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From: South Louisiana/Mississippi
I put a 160 stat in mine also. I had the same problem at standstill. I took the car to my local performance shop (Thunder Racing). We set the fans to come on sooner. The fans come on in stages. The max temp is now 203 on a warm day. All of this was done via laptop. We did several mods at the same time Cags, Torque mgnt, fuel curve, timing etc... 
Pro
Joined: Jul 2007
Posts: 554
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No, you need to change the fan settings with a tune. Your fans only come on at a percentage of what they can do at idle. You need to have them set to come on at full blast at 196*. I DO NOT have a different T-stat, I have the stock one with a tune. My car will not even think of going past 200* at idle, and when its running it stays a constant 190*-196*. You NEED to have those fans reset to come on earlier and at full speed. Trust me, mine runs smooth as glass. It did before my blower, and is identical temp wise after the blower.....NO aftermarket T-stat.
Instructor
Joined: Jan 2005
Posts: 131
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From: Tyler TX
Whatever other issues you might have, I agree with the trapped air responses. Did mine recently and had the exact same thing -- water temp 216 degrees as I was running it with the overflow cap off.
Idled it for a while, even ran it up to 2k for a minute or so and then all of a sudden... "Gulp", the temp went down and I topped her off.
Idled it for a while, even ran it up to 2k for a minute or so and then all of a sudden... "Gulp", the temp went down and I topped her off.
Team Owner
Joined: Feb 2001
Posts: 27,254
Likes: 136
From: Short Hills, NJ
Pro
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Drifting
Joined: Jun 2007
Posts: 1,757
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From: Middletown DE
Mine did the exact same thing...exact same temps that you are getting. I made sure all the air was out of the system.....Blead it about 5 times....Same result. Reprogramming the fan settings is the answer. I did mine with the Predator. The car now doesn't idle a tick over 205 in the heat. Stop and go is around 190 and highway is 176-180.
Team Owner
Joined: Feb 2001
Posts: 27,254
Likes: 136
From: Short Hills, NJ
