my heater was working about like you describe. I did a flush and now it works great. if a flush doesn't fix it, then i would check the blend door.
i have no heat.. 0. being in florida tho i dont feel like paying to fix it when its only cold for like 2 months. but its been in the high 20s the past few morning and its a cold bitch drivin to work with no heat and no defrost. i gota drive with my gloves on
temp gauge goes around 170 and 180 like I want it to and we just drained the fluid and put new. also when I stop the truck at like a stopsign the heater blows cold
You didn't flush it properly. My truck was doing the exact same thing. Get one of those prestone flush kits. It goes in a heater hose. Then u just connect the garden hose while the truck is running. You will be surprised at what comes out. I guarantee that your heat will work correctly after this