Little heat

[mrood1986]

Its cold outside roughly 40 degrees F

When I start my car and let it warm up completely I am not getting much heat out of the vents. Its like luke-warm heat. The fans work and ect.

Anyone know why I am not getting hot air? Thanks


Btw, its a 94 DX 5 speed

[speedy25]

Two reasons- First you didnt indicate if your car gets up to temperature or not. Gauge should read just below halfway. if it doesnt you need a new thermostat.

If not you have no flow in the heater core. This can be because its plugged or the temp control isnt working. If its plugged you may be able to unclog it with a reverse backflush.

-SP

[TrailDust]

Low coolant level can also reduce enough flow to the heating block that it will not function. Check your coolant level to start with....sometimes it's the simplest things....

[mrood1986]

Car is completely warned up and the gauge indicates it as well.
Coolant level is correct.

Should I flush the coolant too? How do I go about flushing the heater core?

[Bitter]

unhook both lines to the heater core and run a hose through them, one way and then the other way, reassemble and then bleed the cooling system of air and add a little straight anti-freeze to combat the plain water from the heater core.

be sure to check the heater control valve, sometimes they don't open fully or they get gunked up. if you hold the engine at 2500rpm when its fullly warmed (after driving 2-3 miles) does the heat get better? does it blow hotter if the fan is on a lower speed?

[speedy25]

Sorry, but ignore bitters flush advice.

If you hook up your hose to the inlet you will push any clogs deeper into the core and you will never get the deposits out. The secret is BACKFLUSH.

Buy a flush and fill kit and some name brand cleaner and FOLLOW THE DIRECTIONS!

And per my previous post, you may not be able to unclog it.

-SP

[Bitter]

I said to flush it both ways, better if you do it multiple times. It doesn't matter which way you flush as long as you flush both ways. I'm citing my knowledge which comes from actually doing this stuff for a living.

[sequoiasoon]

I did that exact thing in my brother-in-laws trailblazer. I followed the lines to see which one fed and which returned. I back flushed first and got CHUNKS of garbage out. Once it ran clear I went normal flow, got more stuff out. Did that 3-4 each way until clear. Heat works great and I told him to go get it fully flushed with new fluid.