hey everyone i got a 1989 iroc z 5.7L 350 automatic. the fans dont work on it so it always gets close to overheating but i always turn it off once it just gets a lil past operating temperature. when i turn it on one fan will turn on for mabey 5 seconds then it slows down & stops n doesnt come on after it doesnt always do this i have no idea what it could be i checked the fuse on the driverside interior n was fine any help?? also i did the timing on it and its running good now but whenever i rev it up a good amount it RPMS will come down n it will go to far down n it sounds like its about to die but it goes back up slowly its weird it never dies though it just sounds like it and it doesnt sound good at all any help please thanks sooo much

 

it would be more helpful if you used some puncuation and thought out sentances. what im getting is your fan turns on briefly, slows, then shuts off? what temp is it reaching? stock, the fans dont turn on until about 245 degrees. gm designed them to run stupidly hot for emissions. as for the revs, how high do you rev it, how low does it droop, and how long does it take to return to idle? what is the idle speed?

 

thanks so much for replying i really appreciate it. sorry for not being the greatest with the punctuation ill try n fix that. first off once the car gets a bit over 220 degrees i shut it off. i had no idea the fans turn on at 245 degrees. tomorrow morning i will let it reach 245 degrees n see if they turn on. so does that mean the the normal operating temp is 245 degrees?? also you are correct how the fan turns on briefly then shuts off. another thing is only one will turn on briefly not both.

now for the revving. i rev it to about 2000rpms or higher. it drops down to about 400 to 500rpms and it stays there for maybe 5 seconds then slowly comes back up. it idles about 800rpms right above 750rpms.

i have the Chiltons for this car and it tells me its supposed to be idleing at 450rpms. to me that doesn't sound right. do you know the correct idle? its an automatic.

 

you have the twin fan setup, correct? do you have a/c, and does it work? turning it on should turn both fans on. 220 is quite normal for these cars in slow traffic, and 240 when sitting and its hot. 260 is when you should start to worry, but i would never let it get that hot. check under the car and make sure the air dam is in place under the rad. its a peice of plastic about 5 inches tall by 3 feet long. but let it get up to temp, and watch when the fans come on. im not sure, but the one fan might have two speed settings, then the other comes on when very hot or the a/c is on. you can rewire them to be on a switch, or get a stand alone fan controller

as for the idle, is that 450 when its in neutral or in gear? its a bit low, but the idle air control valve is working and bringing the idle up. there is a set screw on the driver side of the throttle body. if you screw it in a bit, it will manually adjust the throttle to open a bit more. im betting though the entire throttle could use a good cleaning and that should restore its idle

 

so i tried letting it warm up to normal operating temp and once it got to about 240 one fan came on and the temp dropped. thanks so much i was worried. and for the idle. on the throttle body the screw is blocked by a piece of metal so i cant get to it. i know exactly what you are talking about. on this throttle body it seems like the screw isn't supposed to be touch. i am going to pull the whole throttle body off and clean it. what would you recommend to use for cleaning it???