The latest model vehicles are manufactured with an engine block, and a cylinder head and the head gasket will perform the task of a seal between them. A head gasket is situated between an engine block and a cylinder head, and it is a machined casting used for an internal combustion engine. The main function of the head gasket is to seal oil passage from coolant passage so that the fluid doesn’t get a mix.
What does a head gasket do?
A gasket should be powerful enough to seal the need and prevent leakage between crucial engine parts. They ensure maximum compression is obtained and the gasket is exposed to several elements of a vehicle such as fuel, oil, water and exhaust gases. You need the best header gaskets in your vehicle because it is their task to separate the passage of water and oil through block and cylinder head of an engine.
The gaskets contain compression ratio within the combustion chamber of a vehicle, so they are important. A gasket can blow off due to overheating. In some cases, the water will mix with the oil causing severe damage to the engine. On certain situation, you may find compression in the cylinder creating a hole in the gasket. The usual sign of blown up head gasket is the pressure rising fast in the cooling system.
What happens if head gasket fails?
If the gasket fails, the three liquids will start performing their function, and this may stop the performance of an engine of a vehicle. If the liquids get mixed, the engine can suffer long term deficit.
- If the liquid is lost due to leakage, it may create a messy situation. If the coolant or oil is allowed to stay at a low level, the engine can overheat and wrap components.
- If the oil gets mixed with the coolant, they will contaminate one another. This may cause fatal destruction to the engine.
- If the fuel gets mixed with the coolant or oil, serious engine damage can occur. The result would be broken valves, pistons and other components. You will notice white smoke from the exhaust. The blue smoke indicates the fuel have got mixed with the oil.
How to change a head gasket?
Changing a blown head gasket is a hard job because you will be required to separate cylinder head from an engine block. To get there, you will require removing lots of components. Replacement of head gasket is not a job like do-it-yourself. You have to remove the alternator, power steering pump, and intake and exhaust manifold, wiring going across the cylinder fuel lines and head. Also, you should re-install them perfectly.
Here are given steps to change a head gasket. It is very important to obtain the service manual for your cars make and model. It is good to install LED headlights before you start the process so that you perform the task under proper lighting condition.
There will be images showing step by step procedure to replace the head gasket.
- Step 1 – You must drain all the oil and coolant from the engine. By referring your cars service manual remove the parts connected to a cylinder head. You will need to remove the timing belt also. Make sure you see the alignment marks before you disassemble the components. The cylinder head will be connected with several bolts, and some head bolts must be replaced. Once you remove all the head bolts, lift the cylinder head off the engine block. The gasket will remain a thin piece of ceiling material that can be seen once you remove the head. They can be made of metal or deformable material. The failure can be a break in the gasket.
- Step 2 – Check the head and the block and send the head to an automotive shop to be pressure tested. The head out of specification must be repaired at the shop, and they will also check for the cracks. You should never re-install a cylinder head which is not being professionally examined for cracks.
- Step 3 – You should prepare the surface of head and block. Never scratch or remove any metal because they may prevent the head gasket from sealing. Prevent any debris getting into the cylinder or on piston while cleaning. Make sure you inspect the cylinder walls and piston tops for any damage due to overheating of a gasket.
- Step 4 – Chase the head bolt with a thread chaser to remove the crud. Use compressed air to blow out the crud. It is important to correct the head bolt torque. Then tighten the head to the block.
- Step 5 – Fit the head gasket to the block using a gasket sealant. Make sure you use the sealant specified by the manufacturer and use the directed amount in the particular place. The head gasket will be marked the top and up for proper installation.
- Step 6 – You must correct the bolt tightening sequence and torque for proper gasket sealing. You should use new bolts if needed. You may coat the head bolt thread with few drops of engine oil before installing. You must follow the torque instructions and the way to tighten the sequence.
- Step 7 – Replace other engine components you have removed. You must set the timing belt to proper alignment marks carefully by rotating the camshaft and the crankshaft. Make sure you don’t damage or bend the valves.
- Step 8 – You may fill the engine with new oil and fill the cooling system with factory specified coolant. When you start the engine, keep the engine idle with a heater on full blast. Let the air bubbles go out. Once all air is out of a cooling system, and the engine is stable, check for leaking oil or coolant.
A blown head gasket is a serious problem, and it may have caused due to any mechanical issue in your vehicle. Head gasket problem can damage the engine, so it needs immediate fixing. It can be expensive to have a professional fix so that you may fix it your own.