Heater on my 1997 5.2 is not working. It was blowing warm before I had the timing chain replaced, but now blowing cool. I know the temp control works, because it works on the air conditioning. Where should I look before consulting a mechanic?

Blend door maybe?

Probably an air pocket in the heater core. The heater core is the highest point in the system. Try to find a steep hill or back into a ditch. There is a thread on burping the cooling system somewhere.

That's what I was going to say, maybe an air pocket in the cooling system.

Are both heater hoses hot? What type of thermostat was put back in? You didn't put a Failsafe in did you? They tend to fail really fast and stick open. On my own vehicles where the heater is higher than the radiator, I'll put one of those flush ports at the top. The ones that you hook a garden hose to. Then use a funnel to fill it up. Small air pockets will go through the system and you can burp them out of the radiator cap. Big ones get stuck.

Link to your flush port?

It's a generic kit. You put one of the filler ports in a hose at the high point. On some cars, it really speeds refilling up.

https://www.autozone.com/heating-and...eVehicle=false

Ahh I made one thought yours might be metal how do you cap your end? I just use pvc end cap

There's a cap included on that kit.

I just realized that lol