The heater core is stoped up / MAYBE. Are the engine is low on coolant, Check coolant level in radiator.
Regular coolant or a global coolant will work also. Thanks for your answer. I failed to mention that I have yellow in radiator now, should I stay with yellow? Is there harm in mixing colors?
Green coolant
It uses the ORANGE coolant.
The coolant temp sensor on a 2002 Silverado with the 6.0 engine is located on the drivers side cylinder head close to the front of the cylinder head.
sould be on the manifold
Yes
It is on the right rear side of the drivers side head. BESIDE the BACK spark plug.
Should be in a removable housing at the engine end of the upper radiator hose
It should be part of the distributor.
The green color antifreeze will be just fine.
There is something not right with the engine.