k i just bought an 87 trans am, on the way hoe from buying it the check engine light came on and it would stutter/hesitate to move. left it alone for 20 mins took the parents for a drive in it, it got to 90degrees and kept goin up, i shut the car off b4 it got into the red. under the hood there was a bubbling noise coming from the overflow tank. what the hell is wrong with this pos...i know it needs a new tranny i got that all lined up.

 

water isnt being cooled. had a similar problem with a 92 Firebird i have. I found out the electric fan wasnt kicking on. easiest way to check that is turn on the AC if the fan doesnt start then it needs to be checked. and dont assume its the fan motor. 99% its a relay or bad connection. have fun and hope this helps

 

ok so i checked it with the ac on....the fans dont go on(around 100deg thats teh middle of the guage), but on the back of the ac unit theres that black clip, its unplugged and has a fuse connected to it, what reason would it get disconnected for an have fuse conected to it? i dont want to plug it back in incase it ****s something up. hence the reason its out.

thank you for the help camaro 69. so where should i look now? is tehre a fuse that could be blown not allowing them to go on, or wires disconnected? what and where should i check with a volt meter?

 

Im not 100% sure on the fuse question. behind the A/C i dont have my car around to check at the moment. I'll check tomorrow if i can and let you know about that. But first thing id check would be the fan switch it should be located on the passenger side cylinder head in between the #6 and #8 spark plugs. You may want to run a wire from the battery to the motors to be sure its a relay and not a motor problem. The only fuse im aware of is under the dash. test light can solve if its a bad fuse. or visual whichever you perfer. best part of this its not an expensive problem... just a pain :good luck:

 

thank you for the info, ill check it all out tomroow at work, i only live 2 mins away so it wont even get half way to the temp its suposed to be at

 

forgot to mention , i think the knock sensor is also around there , the fan switch should be a green wire.you can take a look in some other threads and see if thats right.

 

So, let me get this straight: you hear a bubbling noise, but don't visually confirm this in the overflow tank? Just for shoots and giggles, remove the pressure cap, top off the end tank, and start the car. See if it bubbles up. If it does, pressure test the cooling system. If you see a gradual decrease in pressure, run a cylinder pressure test, see how that reads. If there is a cylinder that is significantly lower, you have a blown head gasket more than likely. The bubbles being the result of compression made in the cylinder leaking out and finding its way into the cooling system.

 

i had the same problem with my 84 Z, and al it needed was a new thermostat!

 

Well if it was a blown head gasket itd be more than a temp problem hed be having. also already found out the electric fans not kicking on. also if its bubbling that means the waters flowing through the engine , rules out water pump or thermostat malfunctions. theres no reason to go through all kind of different tests. found 1 problem , its small , fix it and see if that works. I bet its probley either the switch or the rely tho. also the other relay it toward the firewall around the brake booster . Forgot to tell you thats where the actual relay is.

 

ok i looked at what u told me to look for, i couldent see any kind of fan switch all i see are wires, and none of them goin into the cylinder head. although there are a couple of wires goin into a black plastic thing near the top of the firewall by the cowl(abouta foot in on pass side) thats all burnt and looks all Fd up. and i dunno what this relay looks like for the fan on the other side of the brake booster, they all looked fine. only one wasnt hanging on the firewall tho. mabey thats the one thats no good that someone previously tried to fix?

 

ok the relay is just a black box with a plug in it, should be the one farthest to the driverside... think its on the firewall , toward the middle should be the speed sensor neat the back middle of the engine " toward drivers side" then alittle farther either on or right to the left of the brake booster should have another relay which would be your fuel pump relay , should have think 5 wires from it. then on the right of the booster by the driver side should be the fan relay . dont remember how many wires are to it may be 5 also , look for a dark green and white wire if you can tell the colors. sometimes its hard to see the colors of the wires. may need to clean them alittle to see. Anything you find that looks messed up I'd check and replace if you need to , especially relay wise their cheap. Also may want to run to autozone or somewhere and get a haynes repair manual . it shows most the sensor locations and wiring diagrams. previous owners always mean youll find weird stuff done to cars good to have a manual around that shows you how its spost to be stock.

 

forgot to mention sometimes have to look from under the car to find the fan switch. but it should be there around the knock sensor. its just screwed into the cylinder head. the knock sensor wire i think is dark blue tho. Im not sure on that... On the fuse question what color wires are going into it? may be able to figure out what it is. Box on the passenger side should be your map sensor tho