Heater works while accelerating, blows cold when release gas

Try this: put your transmission in low range and drive a couple of blocks at 30 to 35 mph. If you get heat, I would bet on a partially plugged heater core. When you are accelerating, your engine is running in lower.gears at a higher rpm. When you get up to speed, your transmission drops into a.higher gear and the rpm drops. Running in low for a.couple of blocks at 30 mph keeps the engine revving at a higher rpm. If the heat is warm, it is probably a partially blocked heater core.

After quite a bit of searching, this is the only page I have come across that is close to my “issue”.

I have same issue, temp of air suddenly goes cool, BUT, only when i make a moderate to full turn, left or right.

2007 Dodge Caliber SE 2.0L. No issues with engine temp. Coolant level is fine.

Did anyone ever find a solution? I have a 2016 Ford Fusion doing the same thing.

OP, you ever get this fixed? I have you EXACT symptoms.