1980 Fiat 124 2000 Over heating

[redspider8066]

Help!, Ok so everyone told me to burp my radiator after i had drained it to replace the Fan switch which i did. I also replaced the external thermostat on the car and it is still overheating. Am i missing something here? Any information would be greatly appreciated i cant drive it and the weather has been so nice. I am at a loss.
Thanks
Redspider

[4uall]

welcome to the can of worms LOL

this worked for me
http://wwwe.fiatspider.com/f08/viewtopi ... on#p126761

This is todays postings
http://wwwe.fiatspider.com/f08/viewtopi ... =5&t=23072

[pwilliam]

Hey Redspider,

I am sympathetic to your woes. My thread is a long one and I am trying to track down the issues thanks to the help of the great members on the forum. Here are a few things to consider:

Head Gasket: Your head gasket has failed and exhaust gasses are entering your cooling system OR coolant is entering your oil or vice versa. Milky oil on your dipstick is a good sign of coolant getting into the oil. Oil should float on top of your coolant in the expansion tank or radiator.

Another sign would be constantly having to top off your coolant before starting your car each time. Right now I am doing this with my own vehicle..its just a table spoon or so..not much..trying to figure out this problem. With a significantly blown head gasket it will probably be a lot of coolant you are putting in your car.

You can rent a engine leak tester at auto zone if you are still not certain...watch youtube video here: http://www.youtube.com/watch?v=CHp5E7XnbXo

Heater Pipe: You can find a few threads about this. After the car cools, the cooling system will suck air back in via the connection of the heater pipe to the water pump if the two surfaces are not mated perfectly. This will give you air in your system and cause overheating.

Faulty Hoses: When the engine starts to get hot, take a look around at your hoses and see if coolant is misting or spraying form any of them. It will lead to a loss of coolant, obviously, and then overheating.

Radiator Cap: If you have a faulty radiator cap, as I did, it will not restrict coolant from exiting the system into the expansion tank when you go to fill the car at the flush t. It may also allow air to be sucked back in? Others might be able to comment on this, I am not certain. I do know my rad cap was bad because when filling the coolant from the flush t, I could see the coolant level rise in the expansion tank.

Wiring: Try jumping the fan to see if the wiring is good, your sensor may not have been the problem.

As Keith has noted, if you have air in your cooling system after you run it and your temp rises dramatically you probably have a blown head gasket. If you dont have air in your system after running the car, I would guess its something else.

Hope this helps, I'm not an expert...just sharing the things I have come across.

Pete

[redspider8066]

Pete,
Thanks for your input. The temp does not go up very quickly, it takes about 15 min to start to red line. I did notice that the bottom radiator hose is not getting warm at all. I am not sure id the water pump is working. It is not leaking or making any funny noises. The oil is clean so i dont think the head is leaking.I ran the engine and i did not notice much activity of water moving in the radiator when the cap was off.
Any more ideas?
Redspider

[azruss]

If the bottom hose is cold the stadt is not opening. either the stadt is not oriented correctly or you have air trapped underneath. May want to drill an 1/8" pilot hole in the valve so you dont trap air. The valve goes in the bottom radiator hose section

[RRoller123]

Might want to check the internal constrictor on the union where the temp sensor is mounted, at the front of the head. I forget which side the constricted section is supposed to be towards, but someone here will know right away I am sure.

[pwilliam]

Never a bad idea to invest in an IR Thermometer. Test the temp of the bottom of the radiator and the tubes going across the radiator as a starting point, once the temp begins to rise.

If the bottom of your radiator is not getting hot, you might have a blocked radiator, preventing the sensor from getting hot and the lower radiator hose from heating up.

Your water pump may not be circulating water if you dont see movement through the radiator cap.

Checking the restrictor on the t and the thermostat are other good points to check fist. With the IR thermometer you should be able to put your thermostat in a pan of water and see what temp it opens as the water begins to boil. If your stat and your coolant t are properly sorted, you will know you have a different issue at hand.

Good luck!

Pete