99 4.6 cooling issue. When I bought truck guy said heat doesn't work. Bought flush n fill kit since I flush every vehicle I purchase. The plastic tank is full of water. I opened drain petcock and water is just trickling out. So I installed the flushing t and started flush. Water came from plastic tank a little dirty but not too bad. After a few minutes I stopped flush but hardly anything is coming out of drain plug. I've been driving truck a month with zero cooling issues except no heat. Is my thermostat stuck? Any ideas and thanks

 

What does the temperature gauge show while you're driving? You're mixing up cabin heat with engine cooling. They're connected but controlled by different things.

 

The gauge stops dead in the middle on warmup. I don't get warm air in cabin but I'm thinking that's a blend door issue. I have already purchased new door and actuator haven't installed yet I just got truck.

 

Check your heater hoses for heat. That will tell you something about coolant flow through the core. Sounds like your cooling system might be fine. The thermostat is staying closed until the engine warms up then opening to maintain proper temperature.

There are videos out there showing how you can see the shaft of the blend door actuator to see if it's moving. Easy enough and will tell you something. You can also sometimes hear when there's a door problem.

The slow draining from the drain plug is kind of a separate issue. Good luck.

 

Thanks for the input friend

 

Try taking the petcock all the way off and running a zip tie up into and then punch it back and forth as you flush...if you have sediment buildup at the bottom of the radiator it's gonna hit the hole first and build up. I thought mine was thrashed because of this but it cleared right up after a few jabs and started spraying out...

Also, you're gonna have to burp the air out of it to get heat, since the heater core is the highest point in the system..run it up to 3k rpm for a minute at a time then shut it off...start up, rinse repeat. The air should purge out into the expansion tank...it should only take about twenty minutes of this to get the heat working.

 

So the petcock can come all the way out. Idk that thanks much friend👍

 

Should I have cap off tank when I'm burping it?

 

Doesn't really matter, although it seemed to go faster when you leave it on during and take it off just after to let air escape. Like I said only run it for a minute and try not to heat the coolant up when you burp it