Extreme Coolant Loss
Asked by Deepstarr1 Jan 27, 2023 at 04:14 PM about the 1991 Chevrolet Suburban V1500 4WD
Question type: Maintenance & Repair
5.7L. Radiator empties in just a few minutes. No visible leaks anywhere, no coolant in oil, but massive smoke out the exhaust. am I correct in assuming it's most likely a blown head gasket? Thank you, Dan.
2 Answers
On a 1991 model I'd suspect the intake manifold gasket before the head gasket. This engine has a coolant crossover passage incorporated into the intake manifold. To confirm it's not a head gasket use a cooling system pressure tester. With the engine cold pressurize the cooling system then start the engine. If the needle on the pressure tester gauge bounces with the engine running the head gasket is blown. But if not, it's going to be the intake manifold gasket. Hope that helps! Jim
A loss that quick the engine has to dragging it in via a vacuum source and the intake is the most logical choice.