Running cold in winter?

[1974 fj40]

Do any of you have to block to airflow on your 40's to keep the engine temp up
during cold weather?
Mine runs hot enough for the heat to be warm, but yet the needle barely gets past
the C on the gauge.
(This is with short trips to work and back doing 55 on the highway.) If I don't get a lot
of airflow (driving around slowly) the temp rises up a bit into what I would consider the
"normal" range.

Thanks for any input; just curious to hear what your rigs do......

 

[IDave]

Check to make sure the top gasket that goes onto the thermostat within the housing is present. If not, you are bypassing your thermostat and running through the radiator full time.

 

[Paul_A]

My old '70 ran cold with the thermostat. I used to put card board in front of the radiator just to get a little heat. brrrr.

 

[1974 fj40]

I do have both thermostat gaskets, and the thermostat is good as well.

It seemed to run at a "normal temp" all summer, but when the ambient
temp drops my operating temp dips as well. It is as if the fan is just pulling
too much cold air across the rad. and the engine can't heat the fluid quick
enough to compensate for the cooling capacity.

As far as I can tell everything in the cooling system is working correctly.

I am just curious if anyone else, up North maybe, runs colder in the winter.
Or if anyone has to choke off the airflow on the radiator for the winter.

Thanks for the replies so far.........

 

[IDave]

Well, it definitely does run a little colder (it was 6 degrees here two days ago). You can cover the radiator while you are driving, but be careful, once you stop it will overheat easily. Perhaps a half cover would be better.

 

[MJM]

Had The same problem

I had the same type of problem I am in Cleveland, OH so we do get a lillte cold around here. I first changed out the thermostat with a new one and that helped a lot even though my old one seemed to work. Next I had to adjsut the timming a little and that made the difference.
MJM

 

[camcruiser13]

have you thought about an adjustable electric fan, you can choose to have it on or off? just an idea

 

[froggy]

Here we get -20c to -30c (and sometime worst) and My 71 is a freezer
I just can't use it in these conditions. I have the top gasket on and oem thermostat. There is just NO HEAT!!!!!!! Even the ice on the windows doesn't melt BTW, the heater core is so small!!! Maybe the later models are better.....

 

[froggy]

..sorry I forgot... summer or winter, the engine is at 160 F . And please don't tell me to change the thermostat. I tried to many times

 

[IDave]

Yer heater core is probably clogged. Either boil it out, clean it, or replace it, and I'll bet you'll warm up. 160 degrees F is hot! If the core was that hot, you'd be warm.

 

[CruisinGA]

Having a direct drive fan doesn't help much.


My 74 now has a fj60 w/p and clutched fan.

 

[CruisinTiger]

Try changin your fluid, I had a problem with my 60 it was runnin cold a few years ago, didn't think anything of it, till it got down to freezing. Tried to go out and start up the cruiser, the water pump had froozen. So I took a radiator themometor, or barometer, what ever it is called, and found out that the ratio of water to coolent was like 95%water 5% coolant. Changed it and it runs fantastic now. Also how long a drive do you have to work, if it's like 5 miles, that may not be enough for your engine to even get warmed up, try drivin it around 20 or 30 miles and see if you get a different result. Good Luck

 

[airon23]

IDave how do you boil out the core? Is this a pretty task?

 

[IDave]

Boiling out is something a radiator shop would do. Short of that, I'd pour dilute muriatic acid into the heater core, let it sit a half hour or so, then drain it and run a neutralizing solution through it. To do it that way, you do have to pull it out of the truck. You can also run muriatic acid through the whole system, but you have a risk of dislodging gunk from the engine block and having it travel into your core.

 

[BJ70/85]

All good ideas, especially cleaning out your core, it worked for me. I know you have a good thermostat, but could you get a hotter one - maybe a 185 or 195. Check to make sure you have pressure in your system, and that the coolant is full inside the engine-no air lock.