high temp & rotor rust problem?

[gamma_sf]

Hi folks, I need some help with my 1999 Grand AM 3.4L V6.

Problem#1
The radiator fan doesn't start by itself even when the motor gets really hot. I have to turn the air conditionning on so that the radiator fan starts.

This is what I understand........
The cooling fan is controlled by the PCM and will not turn on until the coolant temp reaches pretty close to 230 degrees.

THis seems to be a common problem with GA. Does GM knows about this. Does the high temp (up to 230 degrees) damage the engine or any other parts in the long run. Is it safe to drive at this temp? Or should we always turn on the air condition in city driving even though we live in a cool Bay Area. I also understand that the normal coolant or engine temp (not sure which) for GA is 190 degrees. This is so confusing. Help me understand all this.....

Problem#2

Is it normal for the rotor to rust? I live in a damp city (SF). Can I spray some WD40 or any chemical on the rotor to prevent rusting?

Thanks

[99GrandAMSE]

... I'll just comment on #2, but, it is common for rotors to rust especially if there is a great deal of humidity in the air ... I wouldn't spray ANYTHING on to your rotor under any circumstances and this will affect the stopping capabilities of your car ... if it is just a light 'skim of rust', it will come off the first time you hit the brakes so I wouldn't worry about it :)

[birdhouse]

heh, i have the same problem... my rotors are rusted to shit... not just some corrosion, they're bad. I guess it's time for new rotors, but I just put 2 new ones on 4 months ago when I got my car... I don't think they should be that bad by now...

[Xidion]

If your fan isnt turning on there ither has to be a fulty PCM, Faulty senser, faulty wireing harnes or something else i think, id get it checked out. you shouldnt be letting an engin run at high temps get it to hot end up locking up our engine and then your stranded need a new engine exc.

[gamma_sf]

the fan does turn on when the gauge goes up to 230 or so. Or when I turn on the air condition. It only happens in city driving. I am thinking of changing the thermostat to a 180degree. Will that solve the high temp?

[illsmokeyou]

thatll clear a lot of your problems up. our '03 GT would regularly run 210 here in CA cold weather, and 225 in hot weather, so I think its perfectly normal, and yes as stated, the fan doesnt kick in till 230, which is also normal, but with the 180 therm. I rarely see the needle go past 200, never after 225 even in stop and go traffic, and LA is notorious for BAD traffic