Heater core change

[Rudy913]

How do u change the heater core in a gbody ? And also would that affect the fan speed and my heater not getting hot fast

 

[pagrunt]

Remove the cowl trim & just remove the top of the heater box. GM made it easy by putting it under ther hood unlike earlier A bodys. Might be a bad speed relay module (can't remember the right name) on the heater box. Gotta check coolant levels, if low it takes longer. If the core is bad you should have a smelly fog coming out the vents/ducts & possible inside puddle on the passenger side.

 

[airboatgreg]

Could affect the felt fan speed if evaporator or heater core is plugged with external debris (leaves, pine straw and such)
Not getting hot enough could be plugged core or thermostat not there or stuck open

 

[Texas82GP]

Its not a small job. Here is a good writeup......

http://montecarloforum.com/forum/rwd-tech-guides-70-88-63/g-body-heater-core-replacement-18270/

 

[Longroof79]

Just be careful removing the top of the box...and make sure you find all the hex head screws holding it down. In other words, don't force it.
Airboatgreg is right....you probably have leaves and crap accumulated in the box. You can clean it out and make sure the drain is clear once the screen is removed.
As for the fan speed. I would check the electrical plug on the passenger side of the engine..usually over the intake manifold. Sometimes the connections become compromised and need to be cleaned up and burnished.

 

[Rudy913]

Just be careful removing the top of the box...and make sure you find all the hex head screws holding it down. In other words, don't force it.
Airboatgreg is right....you probably have leaves and crap accumulated in the box. You can clean it out and make sure the drain is clear once the screen is removed.
As for the fan speed. I would check the electrical plug on the passenger side of the engine..usually over the intake manifold. Sometimes the connections become compromised and need to be cleaned up and burnished.

Can u take a pic of the electrical plug?

 

[Rudy913]

Remove the cowl trim & just remove the top of the heater box. GM made it easy by putting it under ther hood unlike earlier A bodys. Might be a bad speed relay module (can't remember the right name) on the heater box. Gotta check coolant levels, if low it takes longer. If the core is bad you should have a smelly fog coming out the vents/ducts & possible inside puddle on the passenger side.

Sometime I see some fog come out the passenger vents and also when passengers ride with me they shoe might get wet

 

[pontiacgp]

do you have AC?... the fog and wet carpet on the passenger side is the heater core leaking or the hose leading to the heater core is leaking at the connection to the heater core

 

[Rudy913]

do you have AC?... the fog and wet carpet on the passenger side is the heater core leaking or the hose leading to the heater core is leaking at the connection to the heater core

I don't have ac ,

 

[Texas82GP]

I don't have ac ,

Much easier project without A/C

1. Disconnect battery ground cable and drain cooling system.
2. Disconnect heater hoses.
3. Disconnect electrical connectors from heater module.
4. Remove module front cover screws.
5. Remove heater core from module.
6. Reverse procedure to install.