Definitely sounds like the heater core is still air bound.

 

Sounds like it was pretty nasty. Instead of a flush, you need a cleaner. You might consider removing the water pump and sticking a hose in both outlets and flush the block. Then use the cleaner as described on the bottle...usually 6 hours of run time. Get a flush and fill kit from Prestone and follow the directions...no burping, drilling holes inthe thermostat, or parking on an incline.

 

You have an air lock in the block. You fill the rad but air is trapped below the thermostat and it won't fill the block. The thermostat won't open because it has no hot coolant flowing across the bottom end. The result is it will overheat and the lack of heat in the heater confirms that the water pump is NOT pumping coolant through the system.

You can do one of two things.

You can remove the thermostat and fill the rad until coolant is flush with the thermostat opening and then install your thermostat and top up the rad. And then any time you open the cooling system, to replace a hose or whatnot, you repeat this.

or,

You can drill a 1/16" hole in the thermostat before you install it. Top up the rad and the air will be purged as you fill. Any time after that that the cooling system is opened you simply top up the. The tiny hole will not affect your cooling whatsoever. Imports have been doing this for decades. Many domestic thermostats come with a bleeder hole. I do this on ANY thermostat that doesn't already have a bleeder.

This ensures that you will NEVER have air trapped in the engine.

The thermostat on the left already has a bleeder hole, the one on the right I have drilled a hole.

You may want to run a garden hose through your heater hoses to ensure the heater core is clear.

 

thanks for the quick replies guys, will definitely
be trying these ideas tonight!

 

Your heater core may need separate flushing with a garden hose. Just pull the heater hoses from the motor and insert a nozzle into one side and watch it flush from the other.

 

Try to stay away from using garden hose water. A lot of people make this mistake with the 4.3s and we'll pretty much any motor. When you use 50/50 it's cut with distilled water. Spend the 5.00 and get 5 gallon or so of distilled water AFTER you do a cleaner and flush.

Sent from my SAMSUNG-SM-G930A using Tapatalk

 

well i did the flush again, flushed heater core, got all the stuff out that i possibly could. did the hole in tstat, filled block up to tstat housing, then filled radiator, let idle for any air to go....filled with coolant and the distilled water and it still ended up going way passed the center mark. coolant was circulating so i believe pump is good, top hose was hot , bottom was hot, so i think the tstat is opening, no visible coolant leaks and my truck does not blow any smoke and oil is good. not sure what i could be missing here, seems like this should be a really basic job to fix but its not going right

 

Am I the only person that can see post 3?

 

I am going to do what you suggested tonight. once everything(including myself) cools down. im getting really ticked off about this and refuse to get beat by this

 

Heater core is not plugged, right? If you put water in one tube, it comes out the other tube just as fast, right? Are you getting any heat inside the cab now? What temperature thermostat did you put in it? It should be a 190 degree.

 

this time, the coolant would be sucked down into radiator, and a couple seconds later come pouring back out, i put the cap on and went inside due to anger of the coolant i just bought being shot out every where.

 

every hose is hot. both heater hoses, upper and lower rad hose. top rad hose full of pressure. can barely squeeze. yes i flushed heater core, came in and went out. NO heat.......it ONLY does this BS when the thermostat is installed !!!!!!!!!! i dont want to drive without the tstat because after a long drive the coolant still gets hot and pours out. im pretty ticked off !!!!!

 

You might wantto take a step back and cool off...no pun intended.

 

Just wondering how many cycles did it take you to bleed it all out? maybe i am just losing my patience each time i see the temp rising so quickly, should i wait a while each time and then keep topping off the system if need be? this is the only thing i havent done yet is continuously check after a while and refill if needed. HOW much coolant should the 4.3 get? right now im at 2.5 gallons

 

Are you asking me? If so, I use the flush and fill kit from Prestone. After the initial fill, I may have to add a pint or less. If your engine was full of crud, you may want to remove the plugs on the sides of the block and loosen junk up wit a coat hanger. It does't take much to plug up the passages.

 

I ask because i just went back out and now i have heat. so im gonna let it cool off and check rad. again

 

Well i give up. did everything suggested and still same result. i flushed out motor and replaced with new coolant, there must be some major debre that i cant get , coolant brown already. any way, i thought i had it because i released some pressure on rad drain and it stayed right below the 210 mark. then went for a drive and zipped to 260, got home and coolant pouring out and i could hear it all boil up. thinking a head gasket leak causing the system to keep building up so much pressure.

 

Another possibility...the impeller in the pump may be toast. Have ou replaced it? If so, is it a reverse flow for a serpentine system?

 

A bad impeller can cause this and as cruddy as your system was it is a strong possibility. I would wager $100.00 (if I were a gambling man) that a water pump will fix this problem. Another thing to consider too, how is the clutch fan, and is the radiator clogged externally? Can you verify whether it has good airflow through the fins? These are also important things to consider.

 

radiator can be clogged internally since hes flushign all sorts of debris around. When you mix orange and green coolant together you get some nasty jello gunk that can very easily clog a radiator...Just because coolant moves from the inlet to the outlet doesnt mean its actually going thru all the tubes efficently.