What is a head gasket?

Basically, an engine is divided into two parts; a cylinder block and a cylinder head.
The block is where the pistons and cylinders are located, and the head is where the valves and rocker arms reside. In between where the head and the block meet, is where the head gasket is located.

The gasket seals both the combustion chamber and the coolant passages in your engine. This means your head gasket has to seal both extremely hot
high pressure combustion gases as well as engine coolant which can be anywhere from cold ambient temperatures to the normal operating temperature of your engine. Due to this, the head gasket develops leaks over time.

The gasket is placed there so that in the event of a mechanical breakdown, the cylinder block and the head can be separated and repaired individually. The head gaskets only job is to seal the area where the two pieces of the engine meet.

The head gasket has to seal the follow three areas
1. The combustion chamber, this is the area where the fuel,
air, spark, and compression take
place, the gasket needs to be able to withstand extreme
temperatures and pressure in this area, so this is the most
common place to have a head gasket failure, or a blown head gasket.

2. The head gasket also seals the coolant passages between
the cylinder block and head, there is not a whole lot of pressure in this area, but sometimes engine coolant can become corrosive due to the
lack of service, and at this point, the coolant can eat away at the head gasket, and eventually it will cause a leak.

3. The last area the head gasket seals is the oil passages, and
again, there is not a lot of pressure in this area. It's rare to have a head gasket leak in this area, if it does, the most common cause is an inferior
product of head gasket. In other
words, the head gasket must have been defective straight from the manufacturer.

What is a Symptom of a Blown Head Gasket?


Engine overheating or exhaust gases in the radiator. If you think you may have exhaust gases in the radiator, the gases would be accommodated by constant
bubbling in the radiator.

Engine running poorly (skipping,
hesitating, or lack of power).

Coolant leaking externally from bellow the exhaust manifold

White smoke from the exhaust pipe.

White milky oil

Significant loss of coolant with no visible leaks

The most obvious visible sign of a blown head gasket would be coolant externally leaking from the head gasket. The head
gasket will be below or inboard of the exhaust manifold.


If the head gasket is blown out completely between the coolant passage and combustion chamber, the cooling system
will build up extreme pressure and possibly blow off the radiator cap, crack the radiator
tank, or blow a radiator hose, whichever is the weakest part of the cooling system, it will fail first.

Usually one of these symptoms by itself is not enough to prove you have a head gasket leak, but if you have multiple symptoms at
the same time it is likely that you have a head gasket leak.

It is important to drive your vehicle as little as possible if you have a head gasket leak. The hot gases and cold coolant moving through the hole in the gasket can quickly erode or warp the metal head or engine block leaving you with costly damages or even having to purchase
new heads or a new engine.

Consequences of not replacing a bad head gasket

Because of the difficulty in diagnosing and the expense of repairing a head gasket, we may be tempted to let it go. This is a big mistake. Depending on the type of failure, far more damage
will soon occur. If coolant enters the exhaust, through the combustion chamber, the catalytic converter(s) is often damaged. Coolant in the engine oil may destroy the engine, by breaking down lubrication.
Combustion gases that leaks into the coolant usually results in continued overheating and more damage. Hydrocarbons entering the coolant will also greatly increase corrosion. This may destroy the radiator, heater core and other expensive components.

Preventing head gasket problems

Replace engine coolant before the pH falls below 7.0

Use distilled water and the proper coolant type only

Always pre-mix coolant and water, before putting in the engine

When an engine starts to overheat, shut it off, IMMEDIATELY

Repair any over-heating conditions immediately

Address any problem with pinging or detonation immediately

When replacing a head gasket, replace head bolts and properly torque the cylinder heads


Blown Head Gasket Sealers or Quick Fixes
If you're looking for a quick fix for a blown head gasket, stop!
There is no such product on the
market, so if you're thinking about using quick silver power, or bars leak, it's only a
temporary fix and could cause more problems down the road like, blockages in a coolant passage, clogged radiator tubes, blockage in the heater core.

You can take your chances with a head gasket sealer in an emergency, but in my personal opinion, you're flirting with disaster! The quick fix may work for a week or two, but you'll pay handsomely in the end.


Fixing a Blown Head Gasket

If the blown head gasket has caused catastrophic damage, a complete engine may need to be installed or a new vehicle purchased.

If the engine is redeemable, the head gasket should be replaced. When replacing, consumers should search by the make, model, and year of the car and obtain the newest generation of head gasket possible along with updated instructions and newer generation tools. Vehicle owners should follow the instructions carefully so as not to damage the gasket during installation or cause damage to the engine in the future. It is always advisable to engage a professional to do the job.

Conclusion
A blown head gasket is a serious issue, as mechanical problems in the vehicle may have caused the problem and will need fixing. In addition, the head gasket problems may have caused engine failure or serious damage to the engine components, and that situation will need addressing. It is a frustrating problem to experience, because fixing it is usually costly and time consuming. Many vehicle owners are not aware of the signs that indicate that the head gasket is failing or has failed, or it could fail so quickly that nothing can be done to prevent it. Because a blown head gasket is so serious, vehicle owners should do their best to perform regularly scheduled maintenance and prevent operating problems before they occur.
In most cases, replacement of cylinder heads and gaskets will be quite expensive. This is due
to their location on modern engines and the amount of labor required to replace them. With over-head and double over-head cam engines, we have to remove the front and top of the
engine gain access. This often includes removing the timing chain[s] or timing belt. In some vehicles we have to remove the engine from the vehicle to gain access.

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