We drive our cars in the Summer Months usually when the weather is warm. We tend to keep an eye on the temperature gauge (if we don't have the mid fifties idiot lights) Then the panic sets in; the engine is overheating.

Well, they did not overheat when they left the factory (except maybe Avanti cars). So what has gone wrong and what can be done to fix the overheat problem.

First you have to determine whether or not your engine is actually overheating. The best way is an infrared heat gun (Canadian Tire). The second best is a candy thermometer in the top of the radiator- best done before the engine gets hot to avoid steam burns etc.

You have of course checked all belts and hoses. Right?

If the engine temperature reads OK on the heat gun but high on the gauge then either the sending unit is bad or the gauge is bad or the wire between the two is corroded.

Just as a aside, When the first Avanti ended up in the dealership with an overheat complaint, the factory fix was to splice a 10 ohm resistor in the line to the gauge. This had the effect of giving a gauge reading much lower than reality!!! Some fix.

Anyway, to move along, many factors cause overheating. The big one is a buildup of sludge in the engine block which prevents the proper flow of coolant. The solution is to remove the two plugs at the rear of the block. You have to remove the starter on V8's. These plugs are very hard to take out. After many years of corrosion they become rusted in place and because they have a square head a normal socket will not fit. I have no solution as to how you get these things out. Maybe somebody out there has done this and can provide a answer.

Once you get them out a coat hanger and lots of flushing will eventually poke out most of the sludge. Generally this will clear up the problem

Next we have cars with a clutch fan. Over time these things fail and the fan just freewheels instead of pushing air like it is supposed to.

The test for this is twofold. First, watch the fan, after the engine is hot. Shut off the engine and observe the fan. If it stops in less than 1 1/2 rotations it is good. If it freewheels for several rotations you need to replace the fan clutch. Next, is the most obvious. Black oily like stuff all over the drive area and sometimes the fan itself will wobble. Replace the clutch drive immediately.

Another thing which is obvious is the thermostat. For racing purposes I use a 170 degree thermostat which was the factory installed Avanti thermostat. These are hard to find and I would suggest a 180 degree quality thermostat and gasket be purchased ( NAPA, Carquest, CTC)

Now we get into the tricky stuff. If your car tends to overheat when driving at high speed on the 400 series highways, then we must look at airflow across the radiator. The solutions are numerous, such as sealing around the rad. support with duct tape in the front of the rad to ensure that all the air actually flows through the rad, not through cracks in the rad frame.

The next thing is to install an air dam such as used on newer cars like the Saturn which has been used effectively on the Avanti.

Overheating at higher speeds is somewhat normal due to higher friction in the engine but if it does significantly overheat at highway speeds then you must look at your ignition timing. Too little advance and the engine will overheat. Too much advance and the engine will overheat but you will know about it due to the detonation induced by too much advance.

Often overheating is caused by external forces such as what is known as parasitic drag. This happens if you have a bad bearing on an alternator, supercharger, water pump or brakes dragging which causes the engine to work harder in order to maintain the speed.

Incorrect or low engine oil will affect engine temperature. This is why race cars usually have an oil cooler. The oil acts as a coolant for the engine.

A carburetor which is set too lean will cause overheating. However not many Studebaker owners meddle with the jets in a carburetor BUT.... fuel containing ethanol will run leaner than fuel without ethanol. Look at the Gas Pump to see if the stuff you are using has an ethanol content and if so try switching fuel suppliers to fuel listing no ethanol.

I could go on and on about overheating and never finish discussing it. The causes are so numerous but I think that I have covered to common causes. If anybody has more to offer please do so.