Overheating...overheating...overheating...

[92 Firebird]

My car has been overheating on and off for a very long time now, and I cannot tell you how frustrating it has been to try and find out why my car insists on overheating. I have done everything I possibly can to try and fix this problem. I have had the water pump changed, the radiator, the fan, the thermometer, the temperature sensor, all that good stuff, and still it gives me a problem and it is not a steady thing, its only when she wants to it seems, its really weird - almost as if she really has a personality all her own.

Everytime I do something it will run good for a few days or weeks, and then go back to overheating. If the air conditioner is on, it overheats faster, but it still does it when the air conditioner is off. If I am at a light sometimes it surges if I have the air conditioner on, and it surges hard too, but if I turn the air off, it stops surging, but continues to overheat. If I don't get her in the wind fast enough, I have to pull her over and wait till she gets cool.

I really need some help here. Does anyone have any ideas what this problem could be? Everything mechanical seems to check out fine, at least that is what my mechanic said last, then he wanted to have the electrical system checked. Do you think it could be that? Do you think I should go ahead and pay the extra expense to have the radiator system flushed out? Could it be the air conditioner? Maybe the condensor? Could it be the coil next to the blower? Would that do it?

Please help me, I am at wits end, and really don't know what to do. Thanks, any help would be appreciated.

[wrightz28]

Have you check the fan(s) operation?

A/C off one (left I believe) should come on about 230ish and off 205-210. If that does not happen I would remove the fan switch connector from inbetween cyls 6 and 8 and ground it. If the fan comes on, the switch is bad.

A/C on, one (right if above holds true) should come on once the system comes up to pressure, ussually no more than 2 minutes.

After that, make sure the air dam is in place and there is no trash inbetween the A/C condensor and radiator.

[92 Firebird]

First let me thank you, I really do appreciate your help and the time you are taking out of your schedule to respond. Call me dense, but I am going to need some further instructions on this one.

Originally Posted by wrightz28

Have you check the fan(s) operation?

The fan is working, I've seen it work when my mechanic had it in his shop, it wasn't overheating, kind of like the tooth when you go to the dentist. When the fan went on it stayed on to keep the car cool, he said it was weird that it didn't shut off. Now, when it is overheating, I couldn't tell you if the fan was on or not because I am driving it.

Originally Posted by wrightz28

A/C off one (left I believe) should come on about 230ish and off 205-210. If that does not happen I would remove the fan switch connector from inbetween cyls 6 and 8 and ground it. If the fan comes on, the switch is bad.

I'm sorry, I don't understand A/C off one (left)? If the fan switch you are talking about is the temperature sensor, then yes, we disconnected that and the fan went on. I changed the temperature sensor just to be sure, but its not that.

Originally Posted by wrightz28

A/C on, one (right if above holds true) should come on once the system comes up to pressure, ussually no more than 2 minutes.

I apologize again, but I don't understand A/C on, one (right) - what do these words mean?

Originally Posted by wrightz28

After that, make sure the air dam is in place and there is no trash inbetween the A/C condensor and radiator.

The air dam - is that the hose that connects from the air filter to the engine block? I had a problem with that once, but it is connected now. Where would I find the A/C condensor? I know where the radiator is. I will look and see if there is any trash between them when I find out where the A/C condensor is. Please understand I am trying to understand, I'm just not as good at knowing what to look for. Thank you again, for your help. I really do appreciate it.

[wrightz28]

Ok, you should have 2 fans, if you only have one, there's half the problem.

Any way, with the air conditioning off, no fan(s) should be on until the engine temp reaches around 230 then one fan will come on and stay on until the engine temp is back down to around 205-210 degrees.

With the air conditioning on, one fan will come on depsnding on the a/c system pressure either immediately or up to a maximum of 2 minutes later and pretty well stay on. And the other fan will come on operate as decribed in the previous statement.

What I recommend doing is to start the car and just let it sit at idle with the hood open, air conditioning off monitor make sure the primary fan works properly.

The air dam, is the large black plastic 'scoop' attached directly under the radiator, hanging down about 5 inches and directs air up in to the radiator.

The a/c condesonr looks like a sort of mini radiator in front of the radiator. Leaves and junk like to collect there after they have been deflected upwards by means of the air dam.

And you are welcome.

[ikeyballz]

oh, and do you have new oil? old, crappy oil will burn up your motor like crazy.. (you prolly do, but its a easy big problem..)

[Blue Bowtie]

The air dam of which Wright speaks (although your's will not be as large):



And the necessary baffles along either side and below the radiator support:



Has teh cooling system been flushed recently? I suspect it has (or at least should have been) with the new water pump and radiator. Was the replacement radiator at least a two-core? Has the intake been removed for any reason? Is the torque converter a stock unit or higher stall RPM replacement?

FWIW, the primary fan turn on with the AC off for your car should be 226°F, turn off at 220°F. That may be warmer than you expect, but those are the factory programmed parameters. Unless there is some other manifestation of overheating, it may not be overheating as much as you think.

What is the temperature gauge indicating? The first makor division at about 1/4-scale of the gauge is 185°F. The center line in the gauge is usually 220°F, and the next major division at the 3/4-scale mark is 235°F. 235° is not necessarily overheated if there is a slight variation between the gauge sending unit and the CTS in the front of the intake (two different sensors).

If you can test the coolant tempoerature reliably, you can check the CTS to verify its accuracy. The resistance of the CTS at a given temperature is as follows:



If the CTS is accurate (or within 10°F) the primary fan should be turning on at 226°, or about 5/8 of full scale on the temperature gauge. As Wright mentioned, the AC high side pressure switch also controls the fan, so with the AC turned on, the temperature at which the fan cycles may be considerably lower.

Another thing to remember is that at 35 MPH the primary fan will shut off. Ram air at that road speed is generally more than adequate to cool the radiator, and the fan becomes a useless electrical load. Again, that depends upon the air deflectors being in place and intact.

[92 Firebird]

Okay, I didn't want to say this, but I happen to be of the female gender and am trying to figure all this out with your guys help. I want to thank you for being patient, and please do not think less of me because I am a woman. I may not know all that you guys know, but I can be intelligent, and am trying. So, thank you for your help.

Originally Posted by wrightz28

Ok, you should have 2 fans, if you only have one, there's half the problem.

I am guessing that the one fan is the one in front of the radiator, and the other fan you speak of is the one that blows the airconditioning into the car.

Originally Posted by wrightz28

Any way, with the air conditioning off, no fan(s) should be on until the engine temp reaches around 230 then one fan will come on and stay on until the engine temp is back down to around 205-210 degrees.

This sounds like this is happening with my car.

Originally Posted by wrightz28

With the air conditioning on, one fan will come on depsnding on the a/c system pressure either immediately or up to a maximum of 2 minutes later and pretty well stay on. And the other fan will come on operate as decribed in the previous statement.

I should probably mention that when this thing happens with my car, I am usually at a light or stopped in traffic or something, and the car surges and then warm air starts coming from the air conditioner. I have to turn the a/c off and open the windows and then pray that we can get in the wind fast enough again so it doesn't overheat.

Originally Posted by wrightz28

What I recommend doing is to start the car and just let it sit at idle with the hood open, air conditioning off monitor make sure the primary fan works properly.

I will try that, thank you.

Originally Posted by wrightz28

The air dam, is the large black plastic 'scoop' attached directly under the radiator, hanging down about 5 inches and directs air up in to the radiator.

How important is that scoop thing? Unfortunately, after they painted my car big pieces of that thing fell off on the left and right sides of the front of my car and I have had them in the trunk ever since just in case they were really important.

Originally Posted by wrightz28

The a/c condesonr looks like a sort of mini radiator in front of the radiator. Leaves and junk like to collect there after they have been deflected upwards by means of the air dam.

I will definitely check that now that I know where it is. Thank you again.

Originally Posted by wrightz28

And you are welcome.

[92 Firebird]

Originally Posted by Blue Bowtie

The air dam of which Wright speaks (although your's will not be as large):



And the necessary baffles along either side and below the radiator support:



Has teh cooling system been flushed recently? I suspect it has (or at least should have been) with the new water pump and radiator.

Thanks for the pictures, they help a lot, at least I was able to know what the scoop thing was. I am not sure if it was flushed when the new radiator was put in, my guess is probably not because the mechanic I go to works out of his garage.

Originally Posted by BB

Was the replacement radiator at least a two-core?

I have no idea. Is that important too?

Originally Posted by BB

Has the intake been removed for any reason?

I do not know that either.

Originally Posted by BB

Is the torque converter a stock unit or higher stall RPM replacement?

Ditto.

Originally Posted by BB

FWIW, the primary fan turn on with the AC off for your car should be 226°F, turn off at 220°F. That may be warmer than you expect, but those are the factory programmed parameters. Unless there is some other manifestation of overheating, it may not be overheating as much as you think.

What is the temperature gauge indicating?

It will go all the way to the red if I let it, but I pull over a few notches before it gets there and let it cool off.

Originally Posted by BB

The first makor division at about 1/4-scale of the gauge is 185°F. The center line in the gauge is usually 220°F, and the next major division at the 3/4-scale mark is 235°F. 235° is not necessarily overheated if there is a slight variation between the gauge sending unit and the CTS in the front of the intake (two different sensors).

If you can test the coolant tempoerature reliably, you can check the CTS to verify its accuracy. The resistance of the CTS at a given temperature is as follows:



If the CTS is accurate (or within 10°F) the primary fan should be turning on at 226°, or about 5/8 of full scale on the temperature gauge. As Wright mentioned, the AC high side pressure switch also controls the fan, so with the AC turned on, the temperature at which the fan cycles may be considerably lower.

I have a feeling the a/c has something to do with it overheating, yes. Please forgive me, but I do not understand. If you will please explain in more basic terms how is my a/c making my car overheat? I am almost sure it has something to do with that, and if I can only get that fixed, life would be so much easier for me. Thank you for your help.

Originally Posted by BB

Another thing to remember is that at 35 MPH the primary fan will shut off. Ram air at that road speed is generally more than adequate to cool the radiator, and the fan becomes a useless electrical load. Again, that depends upon the air deflectors being in place and intact.

These air deflectors you speak of, I am guessing those are the scoop which Wright speaks of, am I correct? If so, I have pieces of that missing. Are they really that important to the cooling of my car? What do I do now? I tried crazy gluing a piece when it was first coming off, but that wasn't happening, also they are made out of fiberglass, so it made my arm itch. What should I do? Thanks again for responding and all your help.

[wrightz28]

92, don't care what gendor you may be, doens't mean a lick. I know females that can put the even biggest "Mr fix-it" to shame.

I gathered that you may not have all that much experience so I tried to keep my answers basic and easy to understand, Blue Bowtie offered up some rather good advice but on a more interdeiate scale, we can still help you out with that too.

You NEED to get the air dam back in place. That is it's primary function, to direct the air at the radiator, and even more important on a firebird than a camaro (less air flow as camaros have the fog light holes to aide).

What seems to be happening here, the fan is working proeprly. But the lack of the air dam (around $35 Us for a new one) is taking it's toll and perhaps the A/c system is low on charge on the comperssor is overworking it. But, first things first, get the air dam back on and go from there.

[Blue Bowtie]

How important is that scoop thing? Unfortunately, after they painted my car big pieces of that thing fell off on the left and right sides of the front of my car and I have had them in the trunk ever since just in case they were really important.

It's a good thing you saved them, since they ARE important. Your's should have looked more like this:

The factory unit is in three pieces - Left, right, and lower (center) deflectors. They are usually held in place by several large plastic push-pin rivets. You can get replacement fasteners at many auto parts stores of the dealership. Oddly, I've even stumbled across them at Lowe's home centers in their miscellaneous fastener/hardware bins.

[92 Firebird]

Originally Posted by wrightz28

92, don't care what gendor you may be, doens't mean a lick. I know females that can put the even biggest "Mr fix-it" to shame.

Thank you for that, it means a lot.

Originally Posted by wrightz28

I gathered that you may not have all that much experience so I tried to keep my answers basic and easy to understand, Blue Bowtie offered up some rather good advice but on a more interdeiate scale, we can still help you out with that too.

Thank you again for that too.

Originally Posted by wrightz28

You NEED to get the air dam back in place. That is it's primary function, to direct the air at the radiator, and even more important on a firebird than a camaro (less air flow as camaros have the fog light holes to aide).

Okay, I will figure out how to get this back on then, thank you for letting me know how important it really is.

Originally Posted by wrightz28

What seems to be happening here, the fan is working proeprly. But the lack of the air dam (around $35 Us for a new one) is taking it's toll and perhaps the A/c system is low on charge on the comperssor is overworking it. But, first things first, get the air dam back on and go from there.

This makes a lot of sense to me, and after I get the air dam thing back on, I will have to find out who can recharge my a/c without overcharging me. Thank you so much for all of your help. You're great to have a conversation with here!

[92 Firebird]

Originally Posted by Blue Bowtie

It's a good thing you saved them, since they ARE important. Your's should have looked more like this:

The factory unit is in three pieces - Left, right, and lower (center) deflectors. They are usually held in place by several large plastic push-pin rivets. You can get replacement fasteners at many auto parts stores of the dealership. Oddly, I've even stumbled across them at Lowe's home centers in their miscellaneous fastener/hardware bins.

Thank you very much too! They do look like that, and there are three parts to them, the left and the right are what fell off, and I believe I only have the middle left over. Do you guys know where I can buy a whole new set up online inexpensively where as I can install it on my own? How hard is it to unfasten those fasteners and fasten them back on? Do I absolutely need a lift for that too? Thank you so much for all of your help!

[wrightz28]

You can do a "parts price request ticket" with the local dealler they usually run 30-50 for camaros, never priced the firebird.

[Blue Bowtie]

No need for a lift, but space is somewhat limited.

http://www.dealsonwheels.com/partsan...GF22LH&cid=530

http://www.dealsonwheels.com/partsan...GF22RH&cid=530

Among others.

The factory P/N for the center section is 14083929. I cannot readily find the numbers for the left and right sections.