torrezdavids

my honda s2000 fan not coming on, and i notice alot of brown sludge coming from the radiator. Please help

Fat

I had to replace the fan motor for the radiator fan because it went out, causing it to overheat. Does the a/c condenser fan (driver side) turn on? If both are not working it may be a fuse.
I'd check the fuses first either way as its free and easy to do. Try hooking the motor to a direct 12v supply and see if it runs. If it doesn't it's most likely dead. It may also be your thermostat, I think you can check that by feeling the lower coolant hoses and if its cold(er) to the touch than the top, that's the issue.
I'm not an expert by any means, but this is just what I've gathered in research when I was diagnosing my issue.

As for the brown sludge I have no idea.

Mexs2k

Brown sludge sounds like a blown head gasket.

Fokker

The easiest way to check if the fans are working is to turn on the AC (the car doesn't have to be running, just with the key in the on position). While the AC is on both fans should spin. If they are working, then you most likely need to change the fan switch (temperature sensor in the lower corner of the radiator). If the fans do not spin when the AC is running, then apply direct 12v to verify that the motors are functioning. If functioning, then you'll need to chase down the electrical system to determine the fault; if not then replace the fans. If the thermostat had failed, you would notice that much sooner under any normal driving conditions as there will be no coolant circulating through the radiator and the car will overheat in a relatively short space.

jyeung528

your radiator taking a shet, get some toilet paper.