54 Commander Still Overheating

I don't know about the radiator fins, but it definitely sounds like an air flow problem. Somehow you're not pulling enough air across the radiator at idle. Are the fan, shroud and pulley all correct/original and intact? If the wrong (larger diameter) pulley or smaller fan was substituted at some point, or if the shroud was altered or omitted, then you would have the kind of problems your experiencing.

If all are correct and intact, the rebuilt engine might just be generating extra heat from tighter clearances. If so, an upgraded fan and/or smaller diameter pulley might help.

S2DSteve

Check the engine idle speed. While the old Stude engines will idle smoothly and quietly at low rpms, a low idle will affect the amount of air being pulled through the radiator as well as the amount of coolant being circulated. The difference between 450 rpm and 550 rpm can be enough to cause a problem.

Jim Bradley

'64 Dayt> I don't know about the radiator fins, but it definitely sounds like an

Is your fan installed properly? Does a piece of paper stick itself to the grille side of the radiator when the engine's running or does it get pushed away? If the fan is on backwards when you're not moving the fan is blowing warm air over the rad and when you're moving slowly the air flow in may be cancelled by the fan pushing out.

Ernie R

Does your car put steam out its exhaust for more than 5 minutes after it is started? Sounds like a problem I had with a friends' Packard. It was ok while driving but would boil over if it idled for more than a couple minutes after it was driven. It's problem ended up being a slightly warped head that would allow exhaust to be blown into the coolant and then at idle the same leak would cause coolant to be sucked into ONE cylinder at idle. This created a vacuum in the cooling system and thus would reduce the boiling point of the coolant. The rule of thumb is your car should run at the temperature that you thermostat is set at until the outside temperature reaches near 100 then you may see it run 5 or 10 degrees hotter. So if your car has a 170-degree thermostat it should always run at that temp unless you idle for more than 10 or 15 minutes. Idling this long will cause a rise in temperature especially if its above 80 degrees outside. However as soon as one starts driving again the car should QUICKLY cool back to the thermostat setting. Of course, this is if everything is operating as designed by Studebaker engineers. A missing thermostat will cause severe overheating problems in a V-8 and it's never a fix to remove a thermostat.

My suggestion is to run a cylinder leak down check on each cylinder. This is completely different than a compression test. A leak down can diagnose a leaking head gasket as well as valve leakage. This can happen even on a newly rebuilt engine. Also do a cooling system pressure check. These tests together can help you rule out a serious problem. This is less expensive than replacing radiators and water pumps. Eastwood sells equipment to do both tests. Or a good old-fashioned mechanic should be-able to these tests as well.

Good luck

Big E wrote:

You might have a head gasket problem if all other possible causes have been eliminated.

JT

Mark wrote:

Ernie, Installing a fan backward won't make it suck instead of blow. Have a look at any auto fan, and then turn it around. The blades will STILL slant in the same direction. (just like a right-hand thread nut stays RH thread if you turn it over).

But a fan WILL be very inefficient if it is installed backwards.

I also seem to remember that there have been a number of defective water pumps sold over the past few years, and possibly the original poster got stung by one of those?

If the car were in my hands, first thing I'd do would be to put a cooling system pressure tester on it. Look for the engine pressurixing the rad, or a system that can't hold pressure.

Gord Richmond

Hi Mark,

Nice meeting you at the show. Hope your problem gets solved. I left about

If you are using molded radiator hoses, make sure the lower hose has a spring inside to keep it from collapsing under suction. Flex hoses have the spring built in. KK