Overheating

[parottthead]

I had my 1982 Spyder out of the garage yesterday for the first ride of spring. I let it idle for a few minutes, and before I could leave the driveway it overheated, spewing water/antifreeze out of the overflow tank. The fan never kicked on. After reading on this forum it looks like a bad ground is the likely culprit for the fan not working. After the car cooled down I removed the radiator cap. The radiator was full with the overflow tank empty. I'm not sure if that indicates anything amiss or not.

Any suggestions are appreciated!

pH

[stefhahn]

oh oh.... I think the thermostate valve is stuck. Did you check whether the hose going down warms up at all? If no - exchange. Fairly common failure after winter.

ciao,
Stefan

[mbouse]

radiator full is no inication that the system is full of coolant. the radiator is not the highest point in this system, and the head frequently gets air trapped inside. the air bubbles create severe cooling problems such as you refer.

if you have not properly "burped" your cooling system, this could be the culprit.

at this time of year, overheating most likely is NOT caused by the fan malfuction.

[parottthead]

I assume changing the thermostat is not any harder than changing one on most cars, so I can do that.
What is the proper way to burp a Fiat?

pH

[pauljdav]

The easiest way is to add a flush kit T (prestone makes them) and the T is installed where the heater hose goes from the cylinder head to the heater. This will be the highest point in the cooling system. The flush kit I got came with a funnel that snaps into the radiator where the radiator cap goes. This enables me to fill the funnel even higher than the T that is on the heater hose.

With the cap on the T removed and the funnel in place on the radiator then you fill the radiator slowly, squeeze the upper radiator hoses to remove bubbles. When the funnel water level is higher than the T , if needed, use a small funnel to full the water at the T. Make sure the heater is set to HEAT so the heater core can fill with water.

Start the car. Continue occasionally sqeezing the upper radiator hoses. As needed fill the funnel on the radiator and the T at the heater hose.

When the engine gets warmer the level in the funnel will get fuller. This is a good time to do a last squeeze on the upper hoses. Make sure the T at the heater hose is full and put the cap on. Then you can either remove the funnel at the radiator and have some water flow to the ground, or you can lower the level with a turkey baster, etc. (I put a low pail under the radiator to catch most of the water).

Put the radiator cap on, make sure your heater is putting out heat, test drive to ensure no overheat problems and you are done.

This method works, and it is easier than removing upper radiator hoses and jacking up the car.

Paul

[parottthead]

Thanks for the info Paul. I will do that method.

[polevaulter999]

another very simple problem to fix that mite b the culprit is the temp sending unit. its the plug at the bottom of the radiator, and if its shot or the wires aren't connected properly, your fan wont turn on. this is what happened to mine, and i just replaced it with a new one from international auto parts for 10 dollars, and it fixed it no problem