Technical STILL Overheating

[Dpendragon]

Someone please help me. I've done all that I know to do.
24 hours after replacing the ignition coil in my 1977 FIat 124 Spider, It began to overheat.
I got her home checked the head gasket (ok) and decided to attack the easiest part first. I found and original Thermostat and put it on.
No Good. She was still overheating.
Then I noticed that the fan wasnt coming on.
Fisrt of all I just had all of the belts replaced and a full tune up including points and hoses. So I know for a fact that the belt is fine to the fan.
I had a friend of mine come over who is an electrician and he tested everything from the battery forward. We even removed the fan and hooked it straight up to the power. It just hummed along fine.
So why wouldnt it come on when the engine gets hot?
Thermal switch.
I replaced the thermal switch, which requires you to drain the radiator.
We put in the new one, refiled the radiator and....
TOO HoT AGAIN!
The switch wont tell the fan to come on.
Here is what I know right now.
THe top of the radiator is HOT. The bottom stays cold.
Today we flushed out the water in the radiator and refilled it and replaced the cap.
The only thing I havent done is put in the cleaning solution for the radiator.
All fluid that has come out of the radiator appears to be sediment free and "clean and Green"
Right now I have her rigged so that if I want to drive her, I open the hood, by pass the switch and connect the wires up, thus turning on the fan, then hop in to go for my ride.
Oh someone please help me?
Does anyone know what finnicky thing I need to do to make her happy???

Thanks so much,
:bang:

 

[narfire]

Someone please help me. I've done all that I know to do.
24 hours after replacing the ignition coil in my 1977 FIat 124 Spider, It began to overheat.
I got her home checked the head gasket (ok) and decided to attack the easiest part first. I found and original Thermostat and put it on.
No Good. She was still overheating.
Then I noticed that the fan wasnt coming on.
Fisrt of all I just had all of the belts replaced and a full tune up including points and hoses. So I know for a fact that the belt is fine to the fan.
I had a friend of mine come over who is an electrician and he tested everything from the battery forward. We even removed the fan and hooked it straight up to the power. It just hummed along fine.
So why wouldnt it come on when the engine gets hot?
Thermal switch.
I replaced the thermal switch, which requires you to drain the radiator.
We put in the new one, refiled the radiator and....
TOO HoT AGAIN!
The switch wont tell the fan to come on.
Here is what I know right now.
THe top of the radiator is HOT. The bottom stays cold.
Today we flushed out the water in the radiator and refilled it and replaced the cap.
The only thing I havent done is put in the cleaning solution for the radiator.
All fluid that has come out of the radiator appears to be sediment free and "clean and Green"
Right now I have her rigged so that if I want to drive her, I open the hood, by pass the switch and connect the wires up, thus turning on the fan, then hop in to go for my ride.
Oh someone please help me?
Does anyone know what finnicky thing I need to do to make her happy???

Thanks so much,
:bang:

I have to get a life,this forum is great.
Anyway, I had a similar issue with my 80 spider. What I found out is two things, first is to raise the front of the car so the rad filler cap is the highest point,fill and run the car till all air is purged. If the car still overheats then look at the thermostat in the rad hoses. Check international auto parts tech bulletin section and look for the fiat cooling system bulletin. It shows all the relevant stuff and fixes for what your describing. It fixed mine.(I drilled a 1/8" hole in the thermostat)
Good luck,this was a 15 minute fix
Chris

 

[Dpendragon]

I didn't find anything about the over heating in the tech bulletins on International auto.
What do you mean raise the car??? How can you make the radiator the highest point?
I've already replaced the thermostat. Its brand new.

The problem from what I can see is that the bottom of the radiator doesn't get hot. So the thermal switch doesn't get warm enough to tell the fan to turn on.

 

[ABZSTILO]

Whilst it does sound to me like the radiator might be at fault, even reconditioned or new ones can have 'issues', what age is the water pump Has it been laid up for a while before this latest work was done Also worth flusing out the heater matrix, I know it doesn't sound related but on a similar engine in a different car (Beta VX) I had a simialr issue which was eventually traced to the heater matrix - odd, I know! But that's Italian cars for you.....
It's possible the water pump isn't pushing the coolant around sufficiently, has the pump been replaced
Also worth checking that the thermostat is working correctly (pan of hot water test should do the job) as I've had new ones that were as much use a chocolate fireguard in the past
Is the pressure cap correct
Certainly narfires' advice is sound, drilling the thermostat can yield good results and getting the front of the car higher than the rest (so park on a steep hill or on some blocks) is a good reliable trick.

If you can, try rigging some temporary pipework which will replace the thermostat completely. Once the car warms up if the radiator is still cold at the bottom/bottom pipe is still cold, then you've either got a blockage somewhere in the block (unusual) or the radiator or water pump is goosed.

Let us know how you get on

 

[narfire]

I didn't find anything about the over heating in the tech bulletins on International auto.
What do you mean raise the car??? How can you make the radiator the highest point?
I've already replaced the thermostat. Its brand new.

The problem from what I can see is that the bottom of the radiator doesn't get hot. So the thermal switch doesn't get warm enough to tell the fan to turn on.

This issue is delt with in the tech bulletin at int. auto.
On the international auto parts web site goto tech bulletins. then scroll down to cooling systems for the fiat(they have alfa stuff as well) then click onto "flushing 124 cooling system" they have the details there.
A hot top hose and cold bottom hose sounds like there is an air lock at the thermostat and its not alowing the coolant to flow. There are various brands of thermostats for the fiat and a couple of them had issues with the air lock as noted in the tech bulletin.
good luck.
chris

 

[Lime green 850]

Someone please help me. I've done all that I know to do.
24 hours after replacing the ignition coil in my 1977 FIat 124 Spider, It began to overheat.
I got her home checked the head gasket (ok) and decided to attack the easiest part first. I found and original Thermostat and put it on.
No Good. She was still overheating.
Then I noticed that the fan wasnt coming on.
Fisrt of all I just had all of the belts replaced and a full tune up including points and hoses. So I know for a fact that the belt is fine to the fan.
I had a friend of mine come over who is an electrician and he tested everything from the battery forward. We even removed the fan and hooked it straight up to the power. It just hummed along fine.
So why wouldnt it come on when the engine gets hot?
Thermal switch.
I replaced the thermal switch, which requires you to drain the radiator.
We put in the new one, refiled the radiator and....
TOO HoT AGAIN!
The switch wont tell the fan to come on.
Here is what I know right now.
THe top of the radiator is HOT. The bottom stays cold.
Today we flushed out the water in the radiator and refilled it and replaced the cap.
The only thing I havent done is put in the cleaning solution for the radiator.
All fluid that has come out of the radiator appears to be sediment free and "clean and Green"
Right now I have her rigged so that if I want to drive her, I open the hood, by pass the switch and connect the wires up, thus turning on the fan, then hop in to go for my ride.
Oh someone please help me?
Does anyone know what finnicky thing I need to do to make her happy???

Thanks so much,
:bang:

Definetly the problem is that the coolant is not circulating through the radiator.
Jacking the front of the car up before filling the rad helps ( to get any air out of the system)
I am suspicios of the new hoses that were recently installed, were they rad hoses? It the bottom hose being succioned close by the engine as it pulls the fluid out of the rad?
Drilling a 1/8 hole in the side of the thermostat could help as well (Allows a small bit of water to pass even if the thermostat is closed).
If not I would look at the water pump to see why the coolant is not circulating.
Finally, I think the system just needs to be "burped" of air to make the coolant flow.

 

[Flyingthere]

Dude from what you have done you have one of two problems. First you put the new thermostate in wrong or you have an air bubble in you cooling system. You can check the thermostate by watching the temp gauge when you hit about 190 degrees you should see the temp drop. If you see the temp drop the bottom hose going into the radiator should be hot at this time. If so then you system is working. If not you need to check the thermostate or your radiator (another subject). Next if you have an air bubble in your system and the air is getting real hot, the car is not really overheating but you can not really tell for sure. you need to bleed the air out of the system. In many cases the only way to do this is to put the front end of the car on ramps and then filling the car with water, squeezing the hoses does not hurt.
Replacing the coil does not have anything to do with the cooling system.
If you are still having problem send me an email and lets discuss.
[email protected]