Thread: Cant get the motor to stay hot. HELP!

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I have a 40 ford coupe with a 350 and a aluminum radiator with AC/Heat combo. In the summer I had a slight over heating issue so I removed the mechanical fan and replaced it with a Walker electric fan and it stoped over heating. Now that its cooler outside (northern California) I cant get the dang motor to stay warm. When the car idels for a few min it will get up to 190-200but as soon as I take off down the road, the motor cools off to about 170 and I cant get any heat in the car. Any suggestions besides changing the thermostat ? My only guess is the thermostat is getting stuck open. I really need some help on this as I take the kids in the car and drive it everyday. Thanks a ton for any suggestions. I'm also looking for an old parking brake handle that mounts on the kick pannel. Maybe from a 45-48 chevy or any old hand parking brake would do.

I would say it is definitely a thermostat problem.
With a proper working thermostat the engine should stay up to temp regardless of the fan ot rad.

Take the thermostat out and check it in a pan of water on the kitchen stove, bring the water to a boil and you can see if it opens and closes properly when it cools down.

Mike

Originally Posted by K9 48 Chevy

I have a 40 ford coupe with a 350 and a aluminum radiator with AC/Heat combo. In the summer I had a slight over heating issue so I removed the mechanical fan and replaced it with a Walker electric fan and it stoped over heating. Now that its cooler outside (northern California) I cant get the dang motor to stay warm. When the car idels for a few min it will get up to 190-200but as soon as I take off down the road, the motor cools off to about 170 and I cant get any heat in the car. Any suggestions besides changing the thermostat ? My only guess is the thermostat is getting stuck open. I really need some help on this as I take the kids in the car and drive it everyday. Thanks a ton for any suggestions. .

I had this same issue with my daily driver, an explorer. I tried about 4 different thermostats. I finally discovered that the "high performance" one is known as a sleeve type and the regular type is a poppet style. I got a Mr.Gasket sleeve type and it made all the difference in the world, the "inexpensive" robertshaw brands are all poppet style and they are either open or closed, the sleeve type will modulate itself and it will also outflow a poppet style at wide open. See if you can locate one at summit or your local auto parts supplier, it will be more expensive but it's worth every penny.

Put some cardboard, vinyl, or something to block the airflow through the radiator. Or buy one of those vintage grille louvers for a couple of $$grand.

Sounds to me like you are just tired of working on it... else you don't want to do anything which could (possibly) reanimate the overheating issue.

Two suggestions:

put the fan on a thermal relay switch. ( if not already )

block at least half the radiator with a piece of cardboard.
( don't forget it when it warms up )

For the winter months I would go to a 192 degree thermostat then switch it out to a maybe 160 when the warmer months come. It is really strange to hear of a '40 Ford that runs TOO COOL, generally these cars have a problem with airflow because of the design of the front end and the engine room trapping air. Says a lot about the efficiency of your aluminum radiator.

Don

PS: Here is a hand brake on Ebay right now that sounds like what you are looking for.

http://cgi.ebay.com/ebaymotors/Flath...Q5fAccessories

Thanks for all the advice. I have owned this thing for a year so far, I did teh card board in front of the radiator and it still wouldnt get hot so I finally broke down and got a 195 thermostat and replaced it however, there wasnt a thermostat in teh F*&^%ng thing to begine with. I cant believe some people when they build a car. I use to race stock cars and we use to remove the thermostat to keep water flowing due to we could only use water and no coolent. I suppose it was cheaper for teh guy to remove the thermostat then get an effective fan. WHen I giot the car it had a mechanical fan on the back and a electric spal fan on the front. I quickly removed the mess and put teh walker fan on and had no issues till it was cold outside. Anyway, than you all for the info. The kids werent complaining today when we went to the video store. As a matter of fact, they were saying it was hot inside. Now it rides at 200 and no issues. Thanks again. I love this site.

An operating temp. of 170 degrees should be plenty hot enough to get heat out of the heater unless there is something wrong with the heater. Check the heater control valve that is in the hose that runs from the intake manifold to the heater for proper operation. If it won't open it won't allow the hot water to circulate though the heater. If the valve is vacuum operated check the vacuum solenoid. My 40 Ford pickup with an aluminum radiator and a 160 degree thermostat would never get hot enough in the winter to get any heat out of the heater. As soon as the thermostat opened the temp would drop like a hot rock. I switched to a 180 thermostat and then it worked fine. In the summer that truck would run at 180 to 185 all day long with the AC on. Griffen aluminum radiator with 1 1/4 tubes, Walker fan shroud and a 17" steel blade mechanical fan.

Allen