I have replaced the radiator,thermostat,all hoses and fan switch on the manifold and my fan motor.my fan still wouldn't turn on so i hooked the fan up so i could tun it on manually with a switch.it helped for a while but it recently started overheating again.I've read this is a comom problem in 305's.I will apreciate any suggestions

 

well u can flush it out too.

or a 180* thermostat if u put in a 195*

make sure your air damn is stil under the radiator

 

Well I have an electric fan that will NOT come on if the key is not at least turned on to where the radio will play. And even then or if I am driving it does not come up until it reaches 220 degrees. Is this normal?
Also the temp usually lingers a little below 220. Where does yours stay?

 

well i don't know much but i do know that the fan turning on at 220 is normal.my temp stay's between the 220 and 100 dash marks.then sky rocket's after 35 min's of stop and go traffic.

 

thanks for the info!
James

 

This thread will show you a pic of where my temp gauge sits most of the time.

What TEMP?? pics plz.. Lets figure it out once and for all

When my gauge goes straight up, the fan kicks on like clock work.

 

Try adding some of those Cooling Additives in the radiator..

 

I've done that. Water Wetter is the product you mention (at last one of them).

It did absolutely nothing to my temp gauge.

 

overheating 305
I have replaced the radiator,thermostat,all hoses and fan switch on the manifold and my fan motor.my fan still wouldn't turn on so i hooked the fan up so i could tun it on manually with a switch.it helped for a while but it recently started overheating again.I've read this is a comom problem in 305's.I will apreciate any suggestions

sounds like you need to replace the fan switch on the lower pass side of engine. costs about 10 bucks at parts store.

 

hellfire,were exactly is this switch. at this point I'm willing to try anything.are u talking about the one that's on the intake?If you are I replaced that one once already but my fan still would not work

 

The fan switch is on the passenger side head right behind the dipstick tube. I'd check out your wiring before replacing the switch too, that's a pretty common area to cook wires.

 

on the intake is the coolant temp sensor, not the fan switch. most people will replace everything before checking this little part. but most of the time it is the culprit. super easy to replace and ill bet it is the cause of your problem.

 

what does the fan switch look like.I took a look and did not find it

 

its on the pass side head underneath. try following the wiring from the fan to the head. i think its between the 6th and 8th cylinders. if i remember it was easiest to get to it from under the car. let me know if this was the problem or you need more help.

 

thank's ,I found itit has one wire(yellow)that looks ok.I tried taking of the switch with a socket but that didn't work .what's the best way to take it off

 

Save urself a loong headache. I got sick of switches so heres an idea: Cut the cord 2 the fan, run a wire into the cab, run down2 ur local parts store an get one of those add-a-circuit things. Hook it up. Now ur fan will come on as soon as u turn the car on. Hope this helps

 

IMO, thats some half *** way to fix a problem. That fan isn't designed to run all the time. One, the car will not reach operating temp as fast as it should, if you have EFI or a cat that will matter. Two, it's added strain on the fan motor/relay/wiring harness.

As mentioned, the fan switch goes bad often and not everyone knows about it.

I don't mean to come off as a jerk, but there's a right way and a wrong way to fix a problem.

Jason

 

https://www.thirdgen.org/newdesign/tech/cool.shtml

Very informative read.. hope it helps

 

LilJayV10, I wish someone had told me about that before I did that. I ran into a lot of problems in behind that. Today I finally found the switch for it. It was in one of the weirdest places, but anyway: Yea, it didnt work like I thought it would. Please folks, IGNORE MY LAST POST!

 

i had the same problem- a 195 degree fan switch from jegs fixed that problem

 

Did the fan just stop workn again? If so u can try running u switch inside ur car to turn the fan on when it gets hot. One comes from the fan motor and the other wire from the fan relay. I'd change the fan switch to. If it ever goes out again u will have that switch to use.

 

I could not resist responding to this one. I have beat this one to death and have the service manaual and all the schematics.

I have two cars and they will overheat. There are the two fans. The primary fan on the left side is controlled by the ECM. The Secondary fan is controlled by the AC Switch and/or the high temperature switch mounted in the head on the passenger's side. What a goofy piece of engineering here.

The sensor for the temp guage on the driver's side head is only connected to the gauge, not the ECM. In fact, I believe this is the same sensor that was used on the 1967 Firebird. Man, what progress!

The second sensor, just for the ECM, is located on the front of the Intake Manifold (TPI), and has two wires. There is no way to correlate what the ECM thinks the temperature is vs the temperature gauge. When the car gets hot or the AC is switched on, the ECM turns on the primary fan. You really do not know if the ECM temperature device works unless you can measure the resistance and correlate it.

Oh, we are not done yet. There's still that sensor on the passenger side head that turns on the fan if the engine raelly gets hot. I think it comes on at 220+ degrees. Now you have two temperature sensors and a switch. Which one is right?

This is about as close to thrid grade engineering as it gets and I am really disappointed in this design. Its just silly. I am looking for a temperature swtich that is set to come on at 190 Deg F, and would like to wire this to come on regardless of the AC. On one of my cars, I have the relay jumped and it runs all the time. Also, these cars are under-cooled. Try driving in Houston in August with the AC on in traffic. I plan to get an Aluminum Radiator and will look at other ways to flow more air.

Oh, and you really think I am nuts on this run. My 91 GTA has a formula hood that is open at the back with a wire grate. It looks really cool. It let's a lot of heat out. I like the hood better than the TA hood anyway. I am thinking about putting some kind of fan system in to vent out more heat there. Heat rises. When putting in more power and headers, there is a real heat build up in these cars. I like the car but its a bad design.

If someone has an idea where I can buy a switch, set at 190 Deg F, that will fit in the head, please let me know. I do not want to put switches in the car because it looks bad and someone else may drive the car and not know about it.

Thanks,

Doug

 

Do a search for hypertech switch, or grand national switch, you should find what you are looking for

 

go to www.JEGS.COM AND GO TO COOLING. THEN CLICK JET FAN SWITCH. IT WILL FIT MOST YEARS CAMARO 82-92 AND IS RATED AT 195*. THE FAN WILL COME ON AT 195 DEGREES!

 

Thanks, I found the switches on Jegs. Looks like they will works.

Doug

 

i still can't take off the switch

 

break the plastic clip, pull the wire off and put on a 13/16 deep socket it will come out.

 

thank's