Signs of a Cracked Cylinder Head
A cracked automobile cylinder head is a major concern, and it's important to recognize early failure signs. The cylinder head contains water ducts, which help facilitate engine cooling, and is bolted to the main engine block. Between the block and cylinder head is the cylinder head gasket, which keeps engine coolant inside the head from contaminating the engine's oil. When the gasket fails, the head's coolant capacity is reduced, causing the metal to overheat and crack.
-
Low Coolant
-
One of the first signs of a cracked cylinder head is a mysterious loss of coolant. The loss is mysterious, because leaks under the parked car are not evident, yet the coolant reservoir is low. This condition can also mean a leaking head gasket, and a mechanic can do a pressure test to confirm the suspicion. Head gasket replacement is a common maintenance repair, and will help prevent the head from overheating and cracking.
Overheating
-
When too much coolant is lost, the vehicle will overheat. Although overheating can be caused by a number of other factors, they can be easily diagnosed by searching for visible leaks. When a car overheats without obvious reason, the vehicle should be checked for a possible head gasket problem. It is overheating that will turn a leaking head gasket onto a full-blown cracked cylinder head.
-
Foamy Oil
-
Oil that has been contaminated with coolant will appear foamy and is one the earliest warning signs. The coolant enters the oil from the leaking gasket or cracked head and makes its way into the oil reservoir. This is where all the non-evaporated coolant goes, which is why ground leaks are not evident.
White Smoke
-
An advanced warning sign of a leaking gasket or cracked head is continuous clouds of white smoke, particularly when the car is first started. The smoke can be less noticeable after the car warms up, but can continue and get worse as the problem becomes more serious. Catastrophic failure of the cylinder head will result in great clouds of white smoke coming from the engine bay, as mass amounts of coolant evaporate on hot metal.
Prevention
-
Regular checking of your car's oil and coolant levels, paying attention to average operating temperature (if the car is equipped with a gauge), can help alert you to many potentially dangerous engine conditions, including head gasket and head condition. A mechanic can perform periodic pressure tests on the system, which is especially beneficial when purchasing a used vehicle, or as part of semi-regular maintenance for your higher-mileage car.
Solution
-
If caught early, cracked or warped cylinder heads can be repaired and resurfaced with good results. This is not always an option for a badly damaged head or under certain high-mileage vehicle conditions. In these cases, a new head or rebuilt engine is often recommended, as other engine parts may be damaged or worn.
-
References
Resources
- Photo Credit Image by Flickr.com, courtesy of Reg Mckenna