1924 Nash six cylinder overheating

[Vintagecarguy]

Hello all,

I am looking into buying a 1924 Nash 690 series sedan. The owner said that the engine was overheating this past summer and that it was caused by the carburetor and/or the heat pipe that comes off of the exhaust manifold. I was wondering if this could be the problem and/or what other things could cause overheating?

Any help would be appreciated.

Thanks in advance. Vintagecarguy.

[Spinneyhill]

Firstly, do you trust the vendor? What did he or she do about it when it overheated? Is the head gasket still OK etc.? Is it for sale coz they can't find the problem or know what it is but don't want to spend the money to fix it? I don't trust people in this situation. You are clearly taking on a fair bit of financial risk with this buggy.

Causes?

Problem in cooling system: blocked radiator or passages in the block, inoperative thermostat, failed water pump, lack of cooling fluid, collapsing water pump inlet hose......

Timing.

Problem with temperature gauge - i.e. is it really overheating.

Water pump drive slipping; fan not right or not operating properly.

Too much paint, or dirt, clogging air flow through radiator core.

Pre-ignition.

Cylinder head gasket upside down (or wrong one) and restricting cooling passages.

Dragging brakes or wheeling bearings.

High friction in engine - too tight or misaligned, heavy oil, poor oil circulation. If they have used non-detergent oil and not changed it for a while it might just be a dirty sludge.

Using an antifreeze solution or other additive that reduces the specific heat of the coolant too much.

Edited October 4, 2016 by Spinneyhill (see edit history)

[Vintagecarguy]

10 minutes ago, Spinneyhill said:

Firstly, do you trust the vendor? What did he or she do about it when it overheated? Is the head gasket still OK etc.? Is it for sale coz they can't find the problem or know what it is but don't want to spend the money to fix it? I don't trust people in this situation. You are clearly taking on a fair bit of financial risk with this buggy.

Causes?

Problem in cooling system: blocked radiator or passages in the block, inoperative thermostat, failed water pump, lack of cooling fluid, collapsing water pump inlet hose......

Timing.

Problem with temperature gauge - i.e. is it really overheating.

Water pump drive slipping; fan not right or not operating properly.

Too much paint, or dirt, clogging air flow through radiator core.

Pre-ignition.

Cylinder head gasket upside down (or wrong one) and restricting cooling passages.

Dragging brakes or wheeling bearings.

High friction in engine - too tight or misaligned, heavy oil, poor oil circulation. If they have used non-detergent oil and not changed it for a while it might just be a dirty sludge.

Using an antifreeze solution or other additive that reduces the specific heat of the coolant too much.

Spinneyhill,

you bring up many good points.

I do know the owner and several people I know know him, so I do trust him. He is selling the car because he has no place to store it.

Thank you very much for your help.

Vintagecarguy.

[Spinneyhill]

OK, that is encouraging. Can you interview the owner to find out the conditions under which it overheated and what was done before it started overheating? There may be some clues to shorten the search.

[Vintagecarguy]

Just now, Spinneyhill said:

OK, that is encouraging. Can you interview the owner to find out the conditions under which it overheated and what was done before it started overheating? There may be some clues to shorten the search.

Spinneyhill,

I will have to talk to him again. He had mentioned that the carburetor and possibly the heat riser causing the trouble. I'll ask him when the overheating happened and post what I find out.

Thanks again. Vintagecarguy.

[Spinneyhill]

If he means the flap in the exhaust that directs hot air up under the carb. to prevent icing on starting on cool days, the cooling system should be able to handle that if it is working correctly. The car will not run as well of course if that valve is stuck open - the air will be expanded slightly and thus there will be less oxygen in the same volume as there is in cold air. That could be the "final straw", probably with a number of other contributing factors. I would be expecting at least a tune up and a full inspection of the cooling system, including the water ways in the block and head.

Edited October 4, 2016 by Spinneyhill (see edit history)

[Rusty_OToole]

You can't put too much faith in what a seller says. Even if he is telling the truth he may not be right, and may be guessing what is wrong.

 

 I would buy the car if it checked out ok and the price was low enough. Even if it needed work,

[Vintagecarguy]

28 minutes ago, Rusty_OToole said:

You can't put too much faith in what a seller says. Even if he is telling the truth he may not be right, and may be guessing what is wrong.

 

 I would buy the car if it checked out ok and the price was low enough. Even if it needed work,

Rusty_OToole,

you make many good points. Thank you for your help.

Vintagecarguy.

[Larry Schramm]

Remember,  All cars " Ran before they were parked"

[Friartuck]

Suggest using an infrared thermometer (a nice noninvasive test) while it is idling. Check outlet and inlet temps (difference) and check for hot spots on the radiator. At least you'll get an idea of what you are buying.

[Rusty_OToole]

Most cars of that era had a hot spot or some means of heating and vaporizing the low grade fuels of the day. Gasoline back then was very low octane, almost like kerosene. Buicks had the intake manifold above the exhaust manifold and the carburetor at the bottom. The intake ran up a pipe that went through the hot exhaust. This pipe could get corroded and leaky over the years, resulting in exhaust contaminating the intake mixture. I don't know what Nash used but Charlie Nash was ex Buick executive and his cars had certain Buick like features like overhead valves. As I say, I don't know how Nash motors were made, am just throwing this out as a possibility.