How do you fix an airlocked radiater. double radiater only one side heating up

The gm 3.4 engine used in that vehicle has a history of a leaking lower intake manifold gasket which results in blown headgasket if not fixed in time. I would start by having a compression test run or by (engine cold) remove radiator cao. Now try to start the engine. If the water spews out then the headgasket are definitely shot. Average repair price is about $1800 usd. Make sure your mechanic uses the new updated gasket set and follows the new torque procedures. I have had 2 of these engines with the exact same issue.

disconnect the heat hoses going into fire wall , put hose into one with pressure and flush as it sounds like it could be bloked in the heater core,the other thing that could be the problem be the hot ,cold switch as it restricts the flow to makes the heater hoter or colder , it might need tlc or replacing as it is manaul not elec

Check your temp sender in case its faulty, but if the enging feels that hot then its could be a number of things. Start with a possibly blocked radiator, or it could be a blown head gasket (is the water system getting pressurised? remove filler cap WHEN COLD and start engine, if it blows the water out or you see bubbles then its a gasket. It could also be that the system is just airlocked (having the header bottle (if fitted) higher than the engine when filling should maybe sort that, also check your heater pipes for bleed scews (fitted if airlocks are a problem on some cars) or maybe youve fitted the thermostat upside down, (check direction of flow). Personally I would go for either an airlocked system or a wrongly fitted thermostat.

two choices.....one is an airlock(undo highest hot hose clip to vent) and the other is a blocked radiator.......

if the main radiator was replaced the heating radiator could be airlocked

first check to see if your heater hoses are getting warm you may just have a bad thermostat, if you've had any recent work done to the cooling system you may have an airlock which does not allow any coolant too flow through the heater core. do you smell antifeeze ?

When engine running, ensure no engine combustion gas bubbles in coolant resevoir (if so, the head gasket is blown).

Check radiator cooling fans are operating ok (as required when car warms up) - if not check
1) fuse,
2) relay operation,
3) heat sensor switch.

Check for collapsing (soft) coolant hose on suction side of waterpump when engine revs above idle.
Check the coolant pressure cap is serviceable & of correct rating,
Ensure cooling system is correctly filled, bleed off any airlocks as necessary,
Check radiator cooling core is not blocked internally or externally.

The generic method of bleeding air from the cooling system is to use a floor jack and raise the front of the car as high as poss, then fill the coolant recovery tank full and run the engine until it just starts to overheat, high end of normal zone on gauge, then shut the engine down and run cold water over the radiator core, this will self bleed the system and the coolant will be pulled from the recovery tank, repeat as necessary, never let the recovery tank run dry or more air will be pulled into the cooling system l , if it still overheats then you need to have the head gaskets checked with a gas analyzer for hydrocarbons present in the radiator or recovery tank

There seems to be an airlock in the system, as for the thermostate you can remove it check it out, fill in some water in a pan,insert the thermostate in it and heat up the water..you will see the thermostate ,if functioning start to open around 82 degrees centigrade or so.
Hope this helps!