Cylinder Head Repair Las Vegas NV

Cylinder head gasket failures are one of the most common mechanical issues facing today’s modern import technician. One reason head gasket failures are common is because the cylinder head gasket itself can become a wearing part. Since the aluminum cylinder head expands at a slightly higher rate than the cast-iron cylinder block, the cylinder head actually slides a few thousandths of an inch across the gasket surface as the engine warms up to operating temperature.

After thousands of thermal expansion events, the fire rings crimped onto the cylinder head gaskets begin leaking combustion gases into the cooling system. All too often, this combustion gas leakage causes the coolant to be forced out when the engine thermostat is closed. When this happens, combustion gas builds up under the closed thermostat and pushes coolant out of the radiator into the coolant overflow reservoir.

In other instances, coolant will be drawn through the worn cylinder head gasket fire ring and be lost into the exhaust system. The net result in either case will be that the engine runs low on coolant, which will cause a major overheating complaint. See Photo 1 .

Photo 1: The presence of a witness mark between the cylinders indicates that the cylinder head gasket is sealing the combustion chamber.

ANALYZING DAMAGE FROM OVERHEATING

Because the damage seldom stops at the cylinder head gasket, it’s important to assess damage to the engine and cooling system before delivering a repair estimate. In severe cases, a “check engine light” complaint might result because oxygen sensors and catalytic converters become contaminated with coolant. In other cases, the rotating assembly in the engine block can be severely damaged by coolant in the oil. This condition normally requires a complete engine repair or replacement.

While exceedingly rare on modern engines, combustion detonation will also aggravate head gasket wear problems and will cause a premature gasket failure. Detonation can be caused by a faulty exhaust gas recirculation (EGR) system, bad fuel or over-advanced ignition timing.

The first step in assessing engine condition is to check the engine oil level. If the oil level is overfull and has an opaque, viscous appearance, it is likely contaminated with coolant. If the oil appears darkened and has a burned smell, it’s very likely that the metal overlays on the engine bearings have softened and peeled away.

A severely overheated engine will also usually emit a burned odor from the radiator or coolant reservoir. If the engine has been severely overheated, it’s also likely that sediment from the water jackets has boiled into the coolant stream and deposited in the coolant reservoir or radiator core tubes. If this appears to be the case, the radiator must be cleaned or replaced to ensure against a continued overheating condition.

If the engine starts, but has a clicking no...