Hey all, I'm having problems with my f150 not getting heat also has a rough idle when cold. I have replaced heater core, thermostat, water pump, fan clutch, flushed the whole system and I still have nothing. Could it be a leak in my intake? Please I need help its cold up in mn.

 

Some good starting points would be to pressure test the cooling system to see if it holds pressure and/or leaks. Are the heater hoses good and warm? I hope you used an OEM (Motorcraft) thermostat because quality is a problem with many aftermarket thermostats.If both hoses are warm, you could have a blend door problem in the dash. Also, I would connect a scan tool, go for a drive sufficiently long enough to warm up the engine. Use the scan tool to determine the actual coolant temperature.It should be around 195-200. Personally, I don't trust dash gauges. If the engine isn't warming up, a code should be stored for it.
Are you losing any coolant? Many times when a head gasket begins to fail, coolant will seep into the combustion chamber after a long shut down and foul the plug(s) causing a misfire till the plug can burn off the coolant. Fuel pressure problems can cause rough idle. Would be worth checking after you can get your cooling system issue resolved and your engine can warm up.
It's a lot but a start.

 

Heater hoses are hot, top radiator hose is hot, bottom is cool. Tested blend door actuator its working. Not losing any coolant. Weird thing is I had the heat working was coming out at 120 degrees but as soon as i went for a drive i lost it all and now cant get it back. i have tried everything i have youtubed about it nothing seems to be working gonna replace the intake gasket and see what happens.

 

Don't mess with the intake gasket right now, it is not your problem.. If your heater and top hoses are hot, you are not losing coolant, it's not your intake gasket. If your vehicle is not equiped with a heat control valve to allow coolant into the heater core (which I doubt) but you can verify because it will be located on a heater hose. Your problem has to be associated with a blend door. Remember, there is two blend doors within the dash if you do not have a control valve on a heater hose..

 

I know of the one where would the second be

 

In the heater box.Like I said, if both heater hoses are hot going into the firewall, the problem is inside the cab and the blend doors route air between the different vents and the other door regulates the amount of hot air flow coming the heater core.Maybe a vacuum line came off the door's vacuum motor, faulty vacuum motor, no vacuum being sent to that blend door or the door is stuck.