HEATER CORE

Hello,

You must start by letting the charge out of the air conditioner.

https://www.2carpros.com/articles/re-charge-an-air-conditioner-system

then get started under the dash removing the heater box along with the heater and ac hoses.

Here is a guide hat will show you what you are in for when doing the job.

https://www.2carpros.com/articles/replace-heater-core

Your car will be a little different but you get the idea.

Please let us know if you need anything else to get the problem fixed.

Cheers, Ken

Hi:
Yes that is the heater core. If you are getting coolant in the car, it is leaking inside too. If you smell coolant through the heater vents, that is the problem. It will need replaced.

Let me know if you have other questions.

Joe

Is this the Lumina Van or Lumina Sedan?

I can't remember if your car has a heater control valve but if it does it should be in the heater core inlet hose. Also, your heater core could be plugged. When your car is idling at normal operating temp and the heat is turned on all the way, are both heater core hoses really hot? If so your core is fine; if one is cooler than the other, your heater core is clogged.
Another possibility is your vent door or your vent door actuator. When you switch from cold to hot do you hear the vent door moving behind the dash? If not look there.

Hi:
Replacing the heater core is an involved process which requires removing part of the dashboard. I recommend purchasing a repair manual (Haynes, Mitchell, Chiltor) before starting. The manual will provide step by step instructions and pictures for part identification.

With the engine running, rear heat on high, and the engine at normal operating temp, feel both heater core hoses. THey both should be hot. If one is cold, there is no circulation to the heater core, thus no heat.

Let me know what you find.

Joe

Not much on your car. Remove hoses the sound panels on pass side. Then floor duct to rear then cover to core. Then remove core.
At bottom of reply you can get manual via internet click on bottom site ie. Manuals.

One way to find out if it's your heater core, is to leave the car idling at normal operating temp, and turn the heat on high; if both heater hoses are burning hot, your heater is probably fine (although it could be leaky which could explain the smell); if one of the hoses is cold or luke warm, your heater core is probably clogged. If there's a heater control valve in your system, make sure it's not stuck closed (the inlet hose will be hot up until the valve, and cold after the valve).

From what you're describing, it sounds like you need to flush your cooling system/heater core, and you may even have to replace the core depending if it's leaking or not. Again, if you have a heater control valve, make sure it's not the culprit. I can't remember if you have one or not.

Good luck