Engine running hot displays on dash....cold air blowing thru vent

Well you need to post more info. What mode is the climate control in? what is the temp set to? Is the engine warmed up to operating temp? Is the coolant filled to the top of radiator and are the hoses going to the heater warm/hot when engine is running?

Dear Tryus,
Check the temperature of the coolant when the engine is hot and has been running, for about 10-15 minutes.
(You need to check the coolant temperature in the radiator.)
Rather than try to take the radiator cap off at that time, better to take it off when you first start the engine, so it does not blow up at you.
This should tell you what thermostat you have in the engine.
In most cases, there are 3 different temperature thermostats, a 160, a 180, and a 195.
It sound like you need to replace yours with a hotter thermostat.
God bless your efforts.

What is this cap on?? Radiator or windshield washer reservoir? Something else?

If the radiator, most newer cars have a plastic bottle or tank that has a "cold" and "hot" level indicated. You should be able to see the coolant level thru the tank. You should NOT need to open the radiator cap if your car has this tank. Add a 50/50 mixture of water and coolant (of a type your car requires) up to the "cold" mark and start the car. Let it run with the heater set to HOT and fan set to HIGH. Continue adding the 50/50 mixture to maintain the coolant level to the HOT level mark on the tank as needed with the engine running. Stop when there is HOT air blowing out of the heater.

If your car does NOT have this tank, you may only open the radiator directly when the engine is COLD. Wait several hours for the engine to cool after shutting off before attempting to remove the cap.

When cold, press DOWN on the cap WHILE turning. Most caps will come off after a 1/4 to a 1/2 turn. Start the engine and set heater HOT and fan to HIGH. Continue to add a 50/50 mixture of coolant to the radiator until the heater blows HOT air. The coolant level in the radiator should be just under (1" or less) from the bottom of the radiator opening.

Was this the info you're looking for?

How do you know it gets hot? Are you going by the temperature gauge on the dash? Or have you checked under the hood and found out the engine really is running hot? ...Reason I ask is, something just doesn't sound right in your description. After just 5 minutes from starting and driving away, the engine would not yet be at normal operating temperature. That would explain the heater not yet warm. But the temp. gauge says hot?
If so, I would replace the temperature sending unit on the engine. the one for the dash gauge, and see if that was the problem-not reading the temp. accurately.
Couple of other things: Are you sure you got all the air out of the coolant system? Start the car with the radiator cap off and let it run until the engine is warmed up fully, then shut it off and install the cap. Does your reservoir tank stay about half full where it should be, between the full-hot and full-cold marks?
If your problem persists. I would have the coolant system pressure tested, and see if you could get a true temperature reading of the coolant when it seems to be running hot.
Good luck.

Hello: The first thing is check the coolant level. Do this on a cold engine, if engine is a 4.9 check both the radiator and the overflow tank. Make sure they are full of coolant. If it is a Northstar engine then make sure the surge tank is full, this may require checking the tank again after bring the engine to operating temperature then let it cool off. DO NOT OPEN COOLING SYSTEM ON HOT ENGINE it could cause serious burns to you.

Touch both heater hoses going to the heater core. They should both be hot. If they are, then the problem is probably a broken or binding blend door or bad blend door actuator. If one hose is hot and the other cold, then the heater core is clogged.

The most common overheating problem with the Northstar engine is a blocked purge line(small hose).The purge line is designed to purge air out of the cooling system.
There is a small diameter hose coming from near the top of the coolant tank (not the cap) ,this is the purge line.
With the engine idling,pull the purge line from the tank,if there is no coolant flow from this small hose,it is blocked and this will cause overheating.
If the hose is clear, check for blockage at the nipple on the tank.Or trace the hose back until you find the blockage.
The hose goes in to the engine to a crossover and comes out the other side close to the thermostat housing,the blockage may be there.

there are no reset codes, did you bleed the air out of the cooling system? if not do this procedure, if that doeasn't fix it u have a failed air temperasture control blend door motor actuator.
The generic method of bleeding air from the cooling system is to use a floor jack and raise the front of the car as high as poss, then fill the coolant recovery tank full and run the engine until it just starts to overheat, high end of normal zone on gauge, then shut the engine down and run cold water over the radiator core, this will self bleed the system and the coolant will be pulled from the recovery tank, repeat as necessary, never let the recovery tank run dry or more air will be pulled into the cooling systeml ,

If the blower was working why did you replace it?
Heat is made by the engine, and then it is sent into the heater core and a fan, blower motor, blows heat into the car.
First - check that the coolant level is full. If not add MIXED coolant.
Then drive a few miles for the engine to get hot.

If coolant level is full, the thermostat might be bad, or the heater core might be plugged.