1988 Camaro radiator switch question
 

My Mom owns a 1988 Camaro 305 and water is backing up into the over flow then back to the radiator. She is on a fixed income and we were told its the radiator fan switch. Does anyone have knowledge about this issue and does that sound right? I see the AC Delco part for this is about 30.00 but I am wondering about the labor and if this sounds like its the problem.

Thank you very much for any advise on this issue.

Do you have more information? The overflow is there to capture coolant and return it to the radiator. That is a normal function, especially in warm weather with the A/C on, or idling for a period of time. Do you have evidence that the engine is overheating (over 240F)? Or loosing coolant outside the system?

Thanks for your quick response according to my step Father he told me the car is over heating up to 240 but its swapping water/coolant back and forth between the over flow and the radiator and you are right this is a normal function. No its not really that warm of weather where this should happen. As far as loosing coolant I dont believe it is. He also stated it has two fans? I used to own a few camaros myself but its been a while I dont remember two fans. Its hard because hes telling me this over the phone and I am not there in person. I have a 95 Vette now my dream car that is in the shop at the moment getting the radiator replaced... I have a great honest mechanic in my area by wow expensive. I would hate to buy this part for them even though it is only $30 to find out its not the radiator fan switch at all. Finding a good mechanic in there area is another issue. There mechanic moved away. He said a guy at a auto parts store told him this is what it was. I want to believe it but still not convinced.

Thanks again.

The fan (or fans, you can visually see if there are more than one) is programmed to come on at 230F. The gauge is probably not more accurate than 10 degrees at best. I would not be too concerned unless 1) the gauge does exceed 250F, or 2) you experience coolant loss. I would check the coolant to make sure it is a proper mix or water and "coolant/antifreeze" and not just water. Also, replace the radiator cap if you see cracks in the neoprene (black rubber) gasket. It's supposed to take a certain amount of pressure before it overflows into the reservoir. If in doubt, replace the cap (non-vented)

turn on the Ac and the fans should come on. If not, then that needs to be diagnosed. If they do, and it still overheats, then there is another problem

is the air deflector on the bottom still there?

Ok. So I just got off the phone with my step father. The thermostat was replaced two months ago. The radiator cap looks good. What he said was its pulling all the coolant out of the over flow tank and he has to keep refilling it. Also he stated the 2nd fan behind the first one is not turning the first fan in front is. It's reaching 260 degrees so yes its definitely over heating. Yes the air deflector is still there. Thanks again for your response.

The cooling fans are controlled by separate sources. The Main fan is controlled by the ECM, mostly as a result of the temperature readings from the engine temperature sensor. The Auxiliary fan is controlled by another sensor/switch on the engine that is fixed at 230F or 238F (depending on whom you ask). That is why one runs, but not necessarily both. Both are also controlled by a pressure switch on the a/c system that turns on the fans if the pressure in the a/c system gets too high. I suspect the auxiliary fan sensor/switch is the one you were told about that needs replacement (?). For what it's worth, I don't think these cars have both fans installed unless they were originally ordered with a/c; the point being that if you aren't running the a/c, you shouldn't even need the auxiliary fan..

the coolant is going somewhere

that needs to be diagnosed

Thank you all for your responses.
 

My step father is making me crazy:icon_screwy:. My Mom used to race cars but lately she has not been doing so well so I cant ask her either. He did replace the radiator cap it was worn. He took the car out today and said that after a 1/2 hour it started to get hot. Dont know what is hot to him cant seem to get a straight answer. I love him to pieces but sometimes...I will be visiting next Saturday God willing and look for myself. He said today that he saw the car dripping underneath while he had it out. I asked is it coolant? He doesnt know. He got home and put something underneath the car and said nothing dripped or he did not have the pan in the right place. He has a beautiful 1969 camaro and I understand they are much easier to work on I could do work myself on my 1967. I have owned 5 camaros myself 67,82,86,88 and 92 and I loved them all and I learned a lot from them as well. I have a 95 Vette now honestly always wanted a Vette but loved my camaros too. Now he thinks its the hose. Again thank you all for your help but when I cant get a straight answer its making me crazy and how can I help them. When I get there I am going to check for myself and see what the heck is going on and I will use all your expertise in the process of elimination. Thank all of you again for the information. :icon_razz:

Still Over heating 1988 5.0 water pump replaced
 

Okay the saga continues. I am at a loss here. My step Father after the water pump was replaced took out the car and all was good until he saw it over heating AGAIN. This is sooooooooo frustrating. He just parked the car and put his hands up in the air. My Mom decided to take the car out again today why? I dunno she just misses driving. Within about a 1/2 hour the temperature was red lining. She said she saw steam coming from the passenger side when it over heated. No steam inside the vehicle so I believe the heater core is fine. They had a guy put in the water pump and fan switch to my understanding and he was supposed to come by last Monday no call no show no excuse. I know the water pump is correct for her year did lots of research and confirmed it was the right water pump I actually ordered it for them. My step father did not buy the vented radiator cap like what was suggested. They had the lower hose replaced as well under the water pump. My step father told me a few people told him it was a cracked block without looking at the vehicle. I told him well I think there wrong, they told me the same thing with my Vette and they were wrong mine was the radiator. To add to this when checking the oil its does not have a mile shake look to it either.

As for the fan switch to my understanding the fan switch was replaced and the car ran cool for a few weeks after the water pump and fan switch were replaced. Is there more than one fan switch? Could this be a fuse? Air dam is in tact.

Does anyone know of a good honest mechanic in the South Bay area of California to be exact Lomita/Torrance?


When I did look under the hood a few weeks back I saw this small amount of coolant to the left of the water pump in a small little crevis if you are facing the car but that could just be where it landed. Thanks in advance for your replies.

My Moms air conditioning unit does not work if I turn it on even with it not working will the fan still come on?

Need to look at the fans when engine is overheating. If they are not working, then there is a problem with the fan motor or the control and power circuits (sensors,wiring, relays, etc..). If they are working, then make sure the air dam in front of the car is still there, they are known for breaking off or people removing them for strange reasons. Make sure there are no air bubbles in the cooling system as they can cause all sorts of weird problems. If the cooling system is in good shape, then there is a possibility of a blown head gasket, which can cause sudden rise in coolant temp. Have the coolant tested for the presence of combustion byproducts as their presence is a sure indicator that exhaust gases are entering into the cooling system. Also make sure you have the a 50% water 50% anty freeze mix in the cooling system as this raises the boiling point of the mixture, and that the proper type of radiator cap is used as the pressure is needed as it also increases the boiling point.
You mentioned there are two fans, one in front of the other. This seems strange to me as usually they are mounted side by side or one in front of the radiator pushing air, and the other behind the radiator pulling air. In any event make sure both fans blow air into the engine compartment and not fighting each other.

Thank you Pete
 

Air dam is still in tact. You are right on there Camaro there is one fan in front of the radiator. They have the 305 coupe. So if my Moms a/c compressor is shot will I still be able to see if the fan is turning by turning on the air even though the a/c does not work? Or is the only way to test the fan is wait until the car gets hot enough to see if it comes on? My understanding is and I will double check this they are using the 50/50 mixture. Can you please tell me the easiest way to have the coolant tested? My step father bought the non vented radiator cap could this make that much of a difference where there car would over heat? I told him to buy the vented cap as someone recommened but he didnt. Thank you for your reply. :D

I don't have a wiring diagram handy for your car, but some AC systems a re set up to turn on both fans automatically as soon as the AC is switched on. Other will turn on just one fan when the AC is switched on, and then turn on the other fan as refrigerant pressure reaches a certain level (which won't happen with a bad compressor). The radiator cap for the system in your car has a double seal, one seals at the bottom of the radiator neck and the other seals the top of the neck. The bottom seal releases at 14 to 16 PSI and allows flow into the reservoir, the top seal does not open so that the coolant can be sucked back into the radiator when things cool off. This link will help.
How Car Cooling Systems Work - HowStuffWorks

Thank you Pete. I will look into the link you sent. I guess it cant hurt by telling them to turn on the air and see if the fan is turning. I suppose the next I can do is also have them let the car reach hot and see if the fan comes on. This one guy that my step Father met and had him replace the water pump and hose will not return my step Fathers calls or mine for that matter. The are on a fixed income and I am trying to help them the best I can although I will not be going to their house for a while I am tied up a bit with my husbands illness and it makes it tough. Thanks again.

One thing you should keep in mind is that usually the only thing that goes wrong is the seals around the shaft or the bearings. If the seal go bad you will notice coolant leaking around the shaft or out of the weep hole under the shaft. If the bearings go bad they will make ugly sounds and eventually allow the shaft to wobble and damage the seals. So, unless the pump is seriously leaking the engine will not overheat as long as the coolant is replaced. Also, when you top off coolant in a system with coolant recovery, it is a good idea to remove the radiator cap and fill the radiator to the top, then replace the cap and fill the catch bottle up to the low mark.