Overheating problems.

[tony-ducks]

Hello,

I am very new to this and would appreciate advice on my current situation. I have a 72 f-100, and use it daily because it is all i can afford. That being said I cannot really afford to bring it in to a mechanic to get it diagnosed.

I run my truck in Ohio. My problem is that my truck does no longer put out heat into the cabin. The temp gauge does not move from its initial low position until about 5 minutes into driving where it will rapidly rise to the middle, and it gets hotter and hotter. I only drive it about 4 miles a day so it doesn't overheat. But it did blow out coolant one time from overheating, from where I do not know. I also no longer get any heat into my truck.

Any suggestions?

[fordman]

i would replace the thermostat. get the same temp stat that you have now. the degrees is marked on the bottom of your old one. and refill with anitfreeze. once it blew out the old antifreeze there probably wasnt enough left init to get the truck warm again. unless you refilled it.

[Dragon]

Center of gauge is about 180.

5 minutes in winter is a great warm up time. Over heating in Winter is not right... unless you don't have enough antifreeze in the engine and the block froze. Remove the Thermostat housing and see if the thermostat works by putting it in a pan of water then heating the pan to boiling to see if it opens. When you start it should be closed. Since you lost some water and got to see your coolant you can now tell if you have enough coolant. A 50% mix is green not faint green more like a new bottle of antifreeze green.

What engine do you have?

[tony-ducks]

is it difficult to replace thermostat?

[Dragon]

Nope 2 bolts and some good dry surfaces with Permatex sealant.

What engine because other tips depend on the engine.

[fordman]

if its a 302 that bottom bolt is a pain to get to some times. like when your stuck on the highway.

[tony-ducks]

The engine is a 305

[70shortwide]

must be a 302... i hope its not a 305, the thermostat would be the least of your problems

[tony-ducks]

Sorry its the small V8 302.

[bumpside]

Just a suggestion. Sounds like your new to working on engines. If so, pick up service manual for your truck and engine. It will be a great help for you. If you can't for some reason, Auto Zone can print out directions for changing your thermostat . Someone here might even be able to scan the section on thermostats for you and post it .

[tony-ducks]

I am new to working on car engines, but i have worked on motorcycles. I really appreciate the autozone tip i didn't realize they could do that.

[MadMaxetc]

I don't want to scare you...just prepair you.

If you are not getting heat in the cab and you are having overheating problems...you could have a pluged up system. I would run a cleaning mix through the system before you pull it appart for the thermostat change.

When you drain the system to replace the thermostat, take a look inside the radiator and see if it looks pluged up or not.

Report back after the change and we will help you out a little more if needed!

[BobbyFord]

It's a good idea to drill a small hole (1/16"-1/8") in the face of the thermostat about 1/4" in from the outer edge and position the hole at the highest point when installing the thermostat in the bore. This will help eliminate any trapped air bubbles.

[Dragon]

So is leaving the hose that goes to the top o the thermostat housing area of the manifold barely loose until the heated expansion of the water forces a leak there. Then all the air is out of the engine.

[fordman]

on the subject of air bbubles inthe coolant system. i have always filled the rad full. thens started the engine with the cap off of the rad. then when the coolant level drops i have finished filling the system. i haven't ever heard of burbing the rad until the past few years. this is a new thing that has come along with the new cars and there sealed systems. thats why all the new thermostat usually have a relief hole in them. to get rid of the air in the cooling system.