Today I found a 6 Cylinder 3rd gen in the junkyard that had a stock cooling fan. I think it was a 1991. I know that the 5.0L H.O. in my '84 Z28 doesn't come on until about 220F. I was wondering if i could put a relay from that smaller engine on my Z28 and have the fan come on sooner.

 

relay won't make a difference-it's the fan thermostat you want to swap-i don't know about v6 fan thermostat,but i kinda remember hearing on here that '86-87 buick GN has fan thermostat of something like 205*-just right for use with 180 or 195* coolant thermostat

 

You can get a switch from another vehicle as above, or an aftermarket one like hypertech, or others than replace the stocker, alternately you could get the dakota digital fan controller and have actual programmable fan temps with its a/c control all tied in.

 

Thanks guys. I'm going to figure something out. I don't want to use an engine fan. I know that.

 

A Wells SW505(autozone) comes on at 220 and is a lot cheaper than the GN switch that comes on at 210. The stock switch for our cars comes on at 230! Also the switch is in the passenger side cylinder head, the driver side has the sender for the gauge. Check out http://www.wellsve.com/custom_search...hp?showall=yes they list all the specs for their different fan switches. Another thing the cylinder heads run about 10 degrees hotter than the rest of the engine, they see coolant last and theres a lot of heat there because of the combustion chambers/exhaust valves

 

Doesnt the auto parts stores list them by temp?
Last one I picked up from napa, is 190deg.

 

hi, im having similar issues all of a sudden my 91 rs 305 tbi is starting to overheat and i noticed my fans arent kicking in till about 230 like factory setup. im needing help to be able to set up a low temp switch so they kick in earlier. does anyone have any suggestions on how to walk a dummy threw it like myself? thanks in advanace

Brandon

 

Changing the fan switch is pretty straight forward it's in the passenger side cylinder head. First and foremost do this on a cold engine! Drain the coolant, get it up in the air and take out old fan switch, put some teflon tape or preferable pipe dope on the threads of the new one and screw it in. Also it's a good idea to unhook the negative battey cable because your wrench will be awful close to the starter wires. But if it just started to suddenly overheat but the fans still come on automatically it's probably something else. Check that the air dam(black plastic that hangs down from the nose) is still there, full of coolant and finally could be a sticking thermostat. Thermostats are so cheap and easy to replace it'd be a good idea to replace it anyways if it hasn't been done it awhile. As for a lower temp switch the SW505 from autozone or a Buick Grand National switch. Also Hypertech makes them to.

 

230 is normal for factory fans to kick on. Goto summit racing, look for Jet Fan switch or Hypertech fan switch, get one that comes on at 190 or 180*.

The car is designed to run that hot. When you say "overheat", what do you mean exactly? If it's not boiling over in the catch can, it's not truly overheating.

rsmith085 said it right, if the fans are coming on and it's just now overheating, it's probably not the fans.