when do fans come on?
Thread Starter
Intermediate
Joined: Apr 2007
Posts: 30
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From: New Bern NC
when do fans come on?
anybody know when my fans are supposed to come on in my 85? i put a new switch in and it went to 215 and they didnt come on. it was rigged up when i got it so i dunno where to start troubleshooting. 215 seems way to hot to me for them to come on shouldnt it be around 200
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Joined: Sep 2001
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From: Athens AL
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Main fan should trigger at 228F
Aux fan in 86 comes in at 238, so I imagine thats what it is in 85 as well.
Aux fan in 86 comes in at 238, so I imagine thats what it is in 85 as well.
Team Owner
Joined: Sep 2001
Posts: 62,159
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From: Athens AL
C7 of the Year - Unmodified Finalist 2021
C4 of Year Finalist (performance mods) 2019
You can either buy a switch advertised in the catalogs for the aux. fan, and wire it to the main fan, or reprogram the chip itself.
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Team Owner
Joined: Mar 2001
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From: Cincinnati, Oh USA
You don't need to tune the fans or have them come on any differently than GM designed them to. One thing you have to get used to in modern cars is the fact that their cooling sytems run at a higher temperature and that it isn't harmful to the engine!!!! All of my previous vettes (I own an 87) had a 180 thermostat, a larger radiator, and a mechanical fan and the coolant stayed at 180 once the thermostat opened. The temps you see make you nervous because your previous cars would have been spouting steam at the side of the road. GM says to shut the engine off and let it cool down if it gets to 260 F. I drive my 87 everyday and for 18 years now and I have never ever seen 260 F. You should keep your radiator clean, as debris catches in them and reduces airflow. I'm lazy and instead of taking the radiator out, I blast water from my garden hose backwards through the radiator several times a year. Look at the a/c condenser radiator too and clean debris and straighten the bent fins. You can see it from below the front of the car.
Drifting
Joined: Oct 2006
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From: Citrus Heights California
I like my engine to run cooler too. So I put in a 160 thermostat and Fastchip programmed the fans to come on at 175. I also intalled a Dewitt's radiator. It never gets over 195 now even at the track. I also have a Hypertech Thermomaster chip that kicks the fans on at 175. It's made to run with a 160 thermostat. It was in my Vette for about 3,000 miles. Nothing wrong with it. I still have the box it came in. I just needed a high performance chip to suit my modifications. If it will fit your Vette you can have it for $50.00 plus shipping which will be $5.00. I will send it USPS priority mail with delivery confirmation. If you or anyone else is interested send a PM.
Last edited by Kool88vette; Apr 21, 2007 at 01:39 AM.
Team Owner
Joined: Mar 2001
Posts: 54,124
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From: Cincinnati, Oh USA
I like my engine to run cooler too. So I put in a 160 thermostat and Fastchip programmed the fans to come on at 175. I also intalled a Dewitt's radiator. It never gets over 195 now even at the track. I also have a Hypertech Thermomaster chip that kicks the fans on at 175. It's made to run with a 160 thermostat. It was in my Vette for about 3,000 miles. Nothing wrong with it. I still have the box it came in. I just needed a high performance chip to suit my modifications. If it will fit your Vette you can have it for $50.00 plus shipping which will be $5.00. I will send it USPS priority mail with delivery confirmation. If you or anyone else is interested send a PM.
Thread Starter
Intermediate
Joined: Apr 2007
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From: New Bern NC
so what you are saying is when im in traffic its normal to run 215 or so??? and ok to do so? what about oil breakdown? i dont want to sound totally ignorant but i guess im not used to knowing exactly what the temp is. also 260 so if it does happen to get 230 or something this is ok?? thanks for the help
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From: Athens AL
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so what you are saying is when im in traffic its normal to run 215 or so??? and ok to do so? what about oil breakdown? i dont want to sound totally ignorant but i guess im not used to knowing exactly what the temp is. also 260 so if it does happen to get 230 or something this is ok?? thanks for the help
Your temps are normal, and these engines are designed to run hotter than older cars were. Oil doesnt breakdown til 250, you are fine.
But 250-260 coolant leads to head gasket problems, so dont let it get there.
Drifting
Joined: Oct 2006
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From: Citrus Heights California
A thermostat is about $5.00 and needed to be replaced. I needed a new custom chip anyway so there was no additional cost to having the fan set to come on at 175. The Hypertech Thermomaster was in the car when I bought it and he gave me the original chip. There is nothing wrong with having your fan on all the time. Look at older cars that don't have electric fans. The Vettes are set to run hot for better emissions. Having a cooler running engine increases HP. When your engine is running at 230 or so your air filter is sucking that hot air through the intake. I like my car running cooler and plan to keep it that way.
Last edited by Kool88vette; Apr 21, 2007 at 07:28 AM.
Drifting
Joined: Oct 2006
Posts: 1,934
Likes: 3
From: Citrus Heights California
click my name, to my site, and read the link on the 160v180 debate, or run a search on thermostats before you go much further, you'll open a can of worms
Your temps are normal, and these engines are designed to run hotter than older cars were. Oil doesnt breakdown til 250, you are fine.
But 250-260 coolant leads to head gasket problems, so dont let it get there.
Your temps are normal, and these engines are designed to run hotter than older cars were. Oil doesnt breakdown til 250, you are fine.
But 250-260 coolant leads to head gasket problems, so dont let it get there.
Team Owner
Joined: Mar 2001
Posts: 54,124
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From: Cincinnati, Oh USA
I own an 87, it has always had a 195 F thermostat and when I am underway, the coolant runs at 195 F. My engine does not run at 230 and if yours does when you are underway, then you should be looking for a problem in your cooling system!!!!!! On hot summer days, stopped, my coolant temp goes to 200 F and drops rapidly when I begin moving. I did install a Stewart water pump and with the OEM pump, my coolant would go to 210 F and take a much longer time to recover to 195. The Stewart pump has 41% more coolant flow than stock. If I let my car idle in the summer, it will get to 238 F, the main fan comes on and the coolant temp drops to 211 F and the fan turns off and it will cycle like that. I have never been caught at a light so long that the fan turns on. GM put the fans in these cars for extended idling in summer temps. When you get underway, and air is passing through the radiator, then the thermostat will regulate the coolant flow and keep the engine very close to the opening temp of the thermostat.
If you see 238 F on normal stoplight waits, check to see if your radiator is packed with debris!!!!!!!!!!!!!!!!!!!
If you see 238 F on normal stoplight waits, check to see if your radiator is packed with debris!!!!!!!!!!!!!!!!!!!
Team Owner
Joined: Sep 2001
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From: Athens AL
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Race Director
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From: The Top of Utah
Originally Posted by Kool88vette
There is nothing wrong with having your fan on all the time. Look at older cars that don't have electric fans.
Except, possibly for some specialized purpose, like racing, stay away from a 160° thermostat in an L98.
RACE ON!!!
Some people cannot be educated! 
