Water in radiator has to be refilled every couple of
days with no leaks found anywhere and it's not
Could be a couple of things, the intake gaskets are a known problem with this engine, it could be sucking coolant right into the combustion chambers when running and the other is blown headgaskets also a common failure, you should look at the engine oil if it is milky colored then it is very likely that the headgaskets are blown, a block check will verify this. If the oil is milky and the block check says the headgaskets are fine then it is the intake gaskets.
Need to get it checked because it sounds like it's leaking into the combustion. Cracked head, block or bad head gasket
With the engine cold, pressurize the cooling system with a pressure tester. The system should hole the pressure for 15 minutes, minimum. While you're waiting, especially if the pressure is dropping, carefully look and listen for the leak. Is the coolant level going down in the radiator or just the plastic recovery tank? HTH. -Jim
It's done, have it crushed.
Looking for a Used Sierra 1500 in your area?
CarGurus has 58,656 nationwide Sierra 1500 listings starting at $1,995.
Search GMC Sierra 1500 Questions
GMC Sierra 1500 Experts
Related Models For Sale
Used Cars For Sale