can i increase radiator fan speed?
robb20102010
03-10-2010, 07:44 PM
got a 2003 alero 3400 V6 would like to increase the radiator fan speed a little. both are maybe at best running at about 30-40 hurtz I just had new upper and lower gaskets and head gaskets replaced and i dont wanna see it running in the half way mark. cooler is always better. the fans are wired straight into my ignition so they run all the time. they just dont run that fast. before i wired them straight into my ignition they were still running at low speed. any help appreciated. thanks
skeeter123
03-11-2010, 08:46 AM
Couple of things...
I recently switched from the stock 195 deg thermostat to a 180 deg thermostat; it now runs a notch below 1/2-way mark. I did this for the same reason you stated; I had the LIM gasket replaced and I wanted the engine to run a little cooler.
Fans can run at low or high speed, PCM will command low speed when temp gets to 220 deg, then high speed at 230. There is a separate relay/circuit for low and high speed, you should check to ensure that the high-speed circuitry/relays are OK, and that your re-wiring job uses the high-speed circuitry. Along those lines, I have noticed that even here in Florida, the fans don't really need to be on all the time; it's only when you're not moving (idling at stopplight, etc.) that temp begins to go up. If everythings OK with the cooling system, once you're going 20-30 mph the breeze itself, in conjunction with the thermostat, is usually enough to keep the engine temp down. (Maybe its different if you're going up a long hill, but we don't have a lot of those around here).
Also, the PCM will turn the fans on when the A/C is turned on. Some have used this to keep the engine temp down while stopped/idling.
And, not sure if you want to go this route but there are companies like DHP that will re-program your PCM to alter the fan turn-on temps. They're mostly for people who are racing their cars. I went for the 180-deg thermostat; didn't have the turn-on temps reset, but it still runs fine, a notch below 1/2; and I'm in sunny Florida.
Hope this helps.
I recently switched from the stock 195 deg thermostat to a 180 deg thermostat; it now runs a notch below 1/2-way mark. I did this for the same reason you stated; I had the LIM gasket replaced and I wanted the engine to run a little cooler.
Fans can run at low or high speed, PCM will command low speed when temp gets to 220 deg, then high speed at 230. There is a separate relay/circuit for low and high speed, you should check to ensure that the high-speed circuitry/relays are OK, and that your re-wiring job uses the high-speed circuitry. Along those lines, I have noticed that even here in Florida, the fans don't really need to be on all the time; it's only when you're not moving (idling at stopplight, etc.) that temp begins to go up. If everythings OK with the cooling system, once you're going 20-30 mph the breeze itself, in conjunction with the thermostat, is usually enough to keep the engine temp down. (Maybe its different if you're going up a long hill, but we don't have a lot of those around here).
Also, the PCM will turn the fans on when the A/C is turned on. Some have used this to keep the engine temp down while stopped/idling.
And, not sure if you want to go this route but there are companies like DHP that will re-program your PCM to alter the fan turn-on temps. They're mostly for people who are racing their cars. I went for the 180-deg thermostat; didn't have the turn-on temps reset, but it still runs fine, a notch below 1/2; and I'm in sunny Florida.
Hope this helps.
robb20102010
03-11-2010, 02:04 PM
Couple of things...
I recently switched from the stock 195 deg thermostat to a 180 deg thermostat; it now runs a notch below 1/2-way mark. I did this for the same reason you stated; I had the LIM gasket replaced and I wanted the engine to run a little cooler.
Fans can run at low or high speed, PCM will command low speed when temp gets to 220 deg, then high speed at 230. There is a separate relay/circuit for low and high speed, you should check to ensure that the high-speed circuitry/relays are OK, and that your re-wiring job uses the high-speed circuitry. Along those lines, I have noticed that even here in Florida, the fans don't really need to be on all the time; it's only when you're not moving (idling at stopplight, etc.) that temp begins to go up. If everythings OK with the cooling system, once you're going 20-30 mph the breeze itself, in conjunction with the thermostat, is usually enough to keep the engine temp down. (Maybe its different if you're going up a long hill, but we don't have a lot of those around here).
Also, the PCM will turn the fans on when the A/C is turned on. Some have used this to keep the engine temp down while stopped/idling.
And, not sure if you want to go this route but there are companies like DHP that will re-program your PCM to alter the fan turn-on temps. They're mostly for people who are racing their cars. I went for the 180-deg thermostat; didn't have the turn-on temps reset, but it still runs fine, a notch below 1/2; and I'm in sunny Florida.
Hope this helps.
sounds great ! ill do that thanks for the help :)
I recently switched from the stock 195 deg thermostat to a 180 deg thermostat; it now runs a notch below 1/2-way mark. I did this for the same reason you stated; I had the LIM gasket replaced and I wanted the engine to run a little cooler.
Fans can run at low or high speed, PCM will command low speed when temp gets to 220 deg, then high speed at 230. There is a separate relay/circuit for low and high speed, you should check to ensure that the high-speed circuitry/relays are OK, and that your re-wiring job uses the high-speed circuitry. Along those lines, I have noticed that even here in Florida, the fans don't really need to be on all the time; it's only when you're not moving (idling at stopplight, etc.) that temp begins to go up. If everythings OK with the cooling system, once you're going 20-30 mph the breeze itself, in conjunction with the thermostat, is usually enough to keep the engine temp down. (Maybe its different if you're going up a long hill, but we don't have a lot of those around here).
Also, the PCM will turn the fans on when the A/C is turned on. Some have used this to keep the engine temp down while stopped/idling.
And, not sure if you want to go this route but there are companies like DHP that will re-program your PCM to alter the fan turn-on temps. They're mostly for people who are racing their cars. I went for the 180-deg thermostat; didn't have the turn-on temps reset, but it still runs fine, a notch below 1/2; and I'm in sunny Florida.
Hope this helps.
sounds great ! ill do that thanks for the help :)
skeeter123
03-11-2010, 03:14 PM
If you're going to replace the thermostat and you haven't done it before, check out this link from the GrandAm section:
http://www.automotiveforums.com/vbulletin/showthread.php?t=919386
You'll probably have to remove the heat shield from the exhaust cross-over. Getting the bottom bolt out of the thermostat housing is a pain. I ended up buying a short 13mm wrench to get it out.
Again, if you haven't messed with the coolant system before, check out:
http://www.automotiveforums.com/vbulletin/showthread.php?t=718130
for how to bleed coolant system. If not bled properly, air pockets may form and you'll have other problems.
Good luck!
http://www.automotiveforums.com/vbulletin/showthread.php?t=919386
You'll probably have to remove the heat shield from the exhaust cross-over. Getting the bottom bolt out of the thermostat housing is a pain. I ended up buying a short 13mm wrench to get it out.
Again, if you haven't messed with the coolant system before, check out:
http://www.automotiveforums.com/vbulletin/showthread.php?t=718130
for how to bleed coolant system. If not bled properly, air pockets may form and you'll have other problems.
Good luck!
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