What are the visible signs to differentiate between a blown head gasket and a blown intake manifold gasket?
A blown intake gasket will cause the engine to run too lean, which in turn will cause drivablity problems. A blown head gasket on the other hand may or may not effect the drivablity of the vehicle and may not set the check engine light. Serious engine damage will occur if you continue to drive a vehicle with a blown head gasket. You can see any or all of these symptoms. White smoke coming from the exhaust, A sweet smell at the exhaust, Loss of coolant, Coolant in the oil, air bubbles in the radiator, engine miss. Either of these conditions may or may not set the check engine light.
