heater thermostat

[2stroke]

Recently I was thinking of putting in a thermostat in the heat side heater core line. It would be a simple install, but I was wondering where I could get one. I've seen them for dirt bikes and other racing engines, but I've never seen a cheap one. Also I would want it to be cooler than most, probably 100-120 degrees. I simply want it to block coolant flow until the engine is warmed up a bit. As it is, if I leave the heat on, the engine will basically never heat up until I start driving, and its not safe to drive (frost on every window, and you can never scrape it all). I've always just left fan off, heat off as long as I remember, but wouldn't it be nice to just start the truck, and come out to a nice warm cab on those -10 F and below days?

 

[intelisevil]

Let me start by saying I have no expertise in this subject . . .

How much water is really flowing through your heater core until the engine's thermostat opens up?

My 5.0 Mounty takes about 5 miles on the highway to get any heat to the interior of the vehicle in temperatures below 40, (about 8 miles in the teens). No difference with a recently replaced 192 degree Motorcraft thermostat.

I think you should look into an engine block heater. Replaces one of your freeze plugs and plugs into a 120 volt outlet. There are also other styles that mount differently. A more expensive option would be a remote starter so you can start your vehicle from in the house a few minutes before you walk out the door.

Keep warm - Summer is coming,
Dan

 

[2stroke]

I don't have an exact answer for you, but heater on (especially with fan on) it could be 5 miles before its fully heated up. With heat off, it will be warm in 5 minutes of idling. Its a big difference. The problem with a block heater is I am almost never anywhere I could plug in. I have no interest in a remote start. I used to have a vehicle with one, and never used it.

 

[intelisevil]

wouldn't it be nice to just start the truck, and come out to a nice warm cab on those -10 F and below days?

That statement is why I suggested the block heater or remote start . . .

I don't have an exact answer for you, but heater on (especially with fan on) it could be 5 miles before its fully heated up. With heat off, it will be warm in 5 minutes of idling. Its a big difference. The problem with a block heater is I am almost never anywhere I could plug in. I have no interest in a remote start. I used to have a vehicle with one, and never used it.

Sitting still at idle you have very little air flowing through the radiator so your engine warms up quickly. I can melt 1/4" of ice off of my windshield after about 2 minutes of idling (heater on to allow circulation of coolant, fan set to lowest to minimize cooling effect) in 20 degree weather.

As you drive you have lots of -10 degree (your number) air (not counting the wind chill factor caused by the speed of the air flow!) flowing through the radiator. Of course it takes longer to warm up. Now add in the barely 'warmer' air in your cab that you're blowing through the heater core (which is just a small radiator). No wonder it takes so long to warm up. As long as the windows are clear I just bite the bullet, hit the road and shiver until I see the temperature gauge move about half way.

Some cold morning if the windows are clear so it's safe to drive, leave your heater turned off until the engine is completely warmed up and then turn on your heater and fan full blast. Now watch the temperature gauge plummet as all of that cold liquid from in the heater system gets reintroduced into the rest of the cooling system.

Dan

 

[2stroke]

Mine wont warm up like yours. Just idling with the heat on, it won't ever start blowing heat when its really cold. The heater core just dissipates too much heat. I've been warming up cars with the heat off since before I got my drivers license. I'd love a block heater, but I rent the basement of a house. I park in the street, and I don't have any way to plug it in. Thanks for the ideas though. I'm either going thermostat, or just doing it the way I always have.

 

[natenkiki2004]

The only way you'll be able to preheat that huge chunk of metal and liquid is to use a plug-in heater and having done a lot of research myself, a soft plug/core plug heater is the best way to go. It gets heat as close to the cylinders as possible and makes a lot of stuff on the top of the engine warm to the touch even well below freezing. They work so well that right after I got mine installed, there was a very cold spell of weather. I plugged it in about 4 hours before leaving and when it fired, it immediately went into warm idle mode, below 1,000RPM. I thought something was wrong but the computer thought that the engine was warm enough.

I have a 1992 Suburban with a 5.7L V8 in it. Before I started learning about cars, I knew enough that it would be a good idea to pre-heat the engine so I got a 200-watt magnetic heater for the oil pan. It does absolutely nothing. The pan a mere 1" from the heater is ice cold. It's simply not enough energy to even heat the oil pan full of oil. Forget about the heat moving upwards into the areas where it really matters. Even if you did heat the oil enough, the moment it gets pumped up to the crankshaft, it's ice cold again.

Unless you have a little 4 cylinder car, anything under 300-400 watts is an utter waste of time. You need to heat the coolant because when the thermostat works properly, there's little movement in the coolant system, aside from the heater core. Once you heat the coolant, it mostly stays in the head and lower intake manifold.

*EDIT*
Beware, installing a frost plug heater element is a pain in the Explorer. Naturally, the only spot is the front passenger side which makes it difficult because of the motor mount. I forgot to plug the cord into mine and it was difficult enough trying to get that attached. You'd have to remove a fair amount of stuff to get at it. The 'easiest' one would probably be the lower radiator hose heater.

 

[larrydd999]

2stroke, if you have a '94 with A/C you already have a heater bypass installed. The vacuum operated valve just in front of the firewall where the heater hoses enter/leave is controlled by the air conditioner, or so I've read. The reason I've read (on this site) is because of going from R12 to R134a the A/C is less efficient. My A/C isn't working right now, but you might try playing with the A/C to see if it's capable of doing what you want, then go from there to make it automatic.