back again.
today i drove my 86 f150 , right now it has no thermostat cause i took it out.
i when i turned the truck off, antifreeze started to bubble up again out of the overflow hole on the right of the truck. guage showed close to hot
i flushed it out the other day ( put the hose in the radiator and flushed it and connected a water hose to the flush and fill kit port on the heater core to thermostat housing hose)
should i have taken off the thermostat housing and flush that out the inside of the block sperately when i flushed it out or just flush it through the flush and fill fit port on the heater core hose leading to the thermostat housing.?

this is reallly getting frusterating cause i cant even drive it for about a half hour or so and it gets hot.

or is there anything i can do to flush it. like open up some drain plugs on the block maybe

 

To do a proper backflush...

Remove radiator cap.

Open the drain on the radiator, drain all the coolant...

Disconnect one of the heater hoses, hook a water hose to it, and let the water come up and through the radiator fill opening. Let it flush untill the water is clear.

Reconnect the hose at the heater core, remove the other, opposite one and repeat.

You don't need a special flushing kit. Just a hose adapter for the garden hose to hook to the heater hoses. You can use a bottle of radiator flush if the radiator is extremely nasty, or at your discression. Follow the directions on the bottle.

Some questions I got to ask you.

Do you have Standard cooling, Extra Cooling, or Super Cooling? Do you have A/C? or was it once equipped with A/C from the factory, and/or dealer?

Are the Radiator hoses in good shape? Not horribly soft? Not bulging?

Does it have a fan shroud? (Not all sixes came with one)

Are the radiator fins in good shape? Any obstructions in the fins? Bugs, dirt, etc... Don't forget to check between the A/C condenser and Radiator if equipped.

How is the Fan Clutch, (if equipped), is it engaging?

Fan Blades in good shape? No rust or cracks?

Radiator cap, in good shape? No cracks in the gaskets? Does it hold 13 LBS of pressure?

Replace your thermostat with the correct factory temperature. 192-195 degrees.

Coolant mixture at the proper 50-50%, or 75-25% (alaska etc) mixes?

Overflow bottle hooked up? Fill the bottle about 1/4 way with the correct mix of coolant.

If you can't answer some of these questions, pictures of your radiator, and fan will help me visualise and tell me which Factory cooling system you have.

Hope this helps.

 

i assume it has standard cooling.
when i flushed the system out i took out the heater core and flsuhed it out because i was told it could be that jamming the system.

it did have ac, the ac pump is gone but the condensor is still there.

the hoses dont look bad.
the top one gets hard when the truck is hot
not soft.

yes has a fan shroud.

the thermostat i took out, i put a new one in it and it still did it

u say radiator fins, u mean the metal tabs on the radiator?
if so there is a small pile of them underneath the radiaitor.

fan blades are in good shape but there is a little play in them , i can wigge the fan

fan clutch?

the cap is good, for what i can see

autozone said i should use full strength antifreeze

over flow is good. thats where the antifreeze is bubbling from the hole on top of it.

shoul di flush the block out sperately or when i flushed it the first time will it be ok?

 

Ok, it has supercooling. A/C on a 300-I6 automaticly upgraded the cooling system to Supercooling.

That's normal. The system pressurizes makes them hard. The hoses shouldn't bulge either, look around where they clamp to the radiator, and/or the thermostat housing etc. Bulging swelling around the clamps etc...

Yep, A/C and Supercooling came with fan shrouds. Standard cooling came with just a fan guard.

Yes, there is a problem, yet to be solved.

The fins is what radiates the heat from the core and lines. The fins touch the core and water passages transferes the heat to the fins. Air passes through the fins thus cooling the fins, thus cooling the water in the passages... etc... If some of the fins are missing, or underneathe the radiator. This is most likely your problem. Get a replacement radiator.

is the play in the fan itself or in the waterpump?

There are three types of Fan systems on these trucks.

A: Flex Fan: On these systems the fan is hard bolted to the waterpump and pully. It will not turn independantly of the waterpump. When the engine is at low rpms, the flex fan is at maximum cooling, but the higher the engine revs up, the flatter the fan blades get, they flex so the engine does not have to struggle to turn the fan. However the Higher the rpm, the flatter the fan gets, so the less it will cool.

B: Fan Clutch:
On trucks equipped with fan clutches, the radiator fan is a hard non-flexible fan attached to a clutch. When the truck is cool, the fan spins freely, independant of the water pump(with the engine off and cold, the fan will spin).

B-1: Thermal Fan Clutches:, when the truck heats up, the clutch will engage, the hotter the engine gets, the less the clutch slips, and the more the fan cools, until the clutch fully engages. The advantages of this system is it saves you gas when the engine is cold, and the fan will not flex flat when it is needed the most. This type Clutch Fan will have a spring on the front closest to the radiator.

B-2: Centrifugal Fan Clutch: not heat controlled. The faster the engine turns the faster the fan turns, until it reaches it's higher limit. The Fan always slips, it will not fully engage. Not as good than the thermal type, but better than Flex fans for cooling. This type clutch fan does not have the spring on the front.

Have it pressure tested, or get a new one. The pressure on this cap, is important. If the cap isn't holding the right pressure the boiling point of the coolant temp is lower.

You shouldn't. Full strength can become gelatanous at certain temp extremes. Unless they are selling you 50-50% readymix antifreeze. You shouldn't mix coolant above 75%, to 25% water.

Sounds good.

If you follow the instructions in the second post in this thread, the block will be flushed out fine.

Sounds like your problem is your radiator itself. If it's got fins missing or out of alighnment, and some of them are at the bottom, then the radiator is shot, and should be replaced.

Also if your truck no longer has A/C, and the compressor is removed. IE: no refrigerant in the system, Remove the condenser out in front of the radiator as well. This will give the radiator, direct flow of air, instead of it having to go through the a/c condenser as well.

 

Is it heating up under certain conditions? My GMC would get too hot just cruising at moderate speeds, but was cool at idle and on the freeway. Turned out I had a diesel fan clutch in there, causing problems. Is there any time that it runs at normal temperatures?

Also timing too advanced can cause overheating. Where is your timing at? Verify your temperatures with an independent gauge. Factory gauges are known for being off. I put in a 192 degree thermostat into my truck, and when warm, the needle barely points to the N in NORMAL.

Make sure you put the thermostat back in. It also keeps water in the radiator longer to cool it more. I was from that train of thought, but learned soon enough that the thermostat is a good thing.

I also agree, try the radiator. It sounds shot. If that is not your problem, you probably need a new one anyway.

 

if i drive my truck for a continuous period of time, it keeps getting hotter and it wonrt stop rising until i turn the truck.

but i got like a row or at least a half of row of metal fins gone. is there any way i can test the radiator myself to see its bad.

 

No need to test it. It's bad. The missing fins makes it bad. It won't cool properly with them missing. The fins help radiate the heat away.

You could take it to a radiator shop to flow test it, but with the missing fins, it would be a waste of money to test it.

 

could the radaitor stilll be bad even though its still flowing the antifreeze

 

Yes.

A bad radiator can have one or more of the following problems.

1. Cracks or Leaks
2. Plugged or partially plugged
3. Missing or damaged Fins or other components
4. Severe Corrosion

 

on the new radiator i boght i was trying to take off the trans fluid cooler line ( line returning to the tranny ) end that screws into the radiator so i can use the original ends that are on the lines and the end rounded off, the thread that screws into the radiator is fine but the the part where u would put a wrench on to loosen it is rounded off. whats the best way to remove it so i can put the new radiator on?