The 1993 Acura Integra came with a 1.8-liter four-cylinder engine and a five-speed automatic transmission. The engine block in your Integra has an outer shell with casted sleeves in the center that each piston travels up and down in. Coolant is pushed around the outer sleeves and through the rest of the engine to help keep the engine at a stable operating temperature. A cracked block generally results in a loss of coolant without a puddle to justify such loss; however, a cracked or blown head gasket will often exhibit the same signs.
Loss of Coolant
A loss of coolant can be attributed to several different problems and is not limited to internal engine damage. If you constantly have to add coolant, or have noticed your coolant becoming low, check where you park and within the engine compartment for signs of leaking or spraying coolant. The cooling system in your Integra is a sealed system so a loss of coolant is either coming from outside of the engine or is being lost within the engine. If there is no external coolant loss or any coolant puddles after parking chances are you either have a blown head gasket, cracked cylinder head or cracked engine block.
Coolant to Oil Contamination
Anytime coolant is being lost internally in the engine there is only so many places it can go. A cracked engine block will permit coolant to leak through the engine block and into the oil passages or crankcase. Pull your oil dipstick and check the condition of the oil, a milky like substance on your dipstick is a tale tale sign that coolant has been entering the oil. Coolant can only join with oil in your 1.8-liter through a crack in the engine block or a failed head gasket. If there is coolant mixed with your oil, the engine may still be saved if a faulty head gasket is the cause. Drain the coolant contaminated oil and fill the crank case with fresh oil until a repair or tear down can be performed. Coolant will damage the main crank shaft and connecting rod bearings if you continue to drive the vehicle with coolant in the oil.
Coolant Burning
Anytime the engine runs and there is a white cloud of smoke from the exhaust it means coolant is escaping into the combustion chamber and is being burned off during the combustion process. Coolant can enter the combustion chamber through a blown head gasket, cracked cylinder head or crack in the upper portion of the engine block. Until the root cause can be determined do not start or drive the vehicle any more than necessary as burning coolant will make problems worse if the engine block isn't cracked.
Bottom Line
In the end your 1.8-liter may display several signs that could be a sign of a cracked engine block, but in the end it is impossible to tell whether the cylinder head, head gasket, or block are at fault without tearing down the engine and visually inspecting the components. Your 1.8-liter was designed with a thicker block which means it will not likely be noticeable from outside of the engine, but the internal cylinder sleeves are not as thick. If caught early enough most internal components can generally be re-used whether the block, head or head gasket need replaced. In most cases a cracked block, cylinder head or head gasket are the result of over heating at one point or another.
